Method for hydrosilylation of aliphatically unsaturated alkoxysilanes and hydrogen terminated organosiloxane oligomers to prepare alkoxysilyl terminated polymers useful for functionalizing polyorganosiloxanes using an iridium catalyst

ABSTRACT

A method for preparing a product includes combining starting materials including A) a siloxane oligomer having silicon bonded hydrogen atoms, B) an alkoxysilane having at least one aliphatically unsaturated group capable of undergoing hydrosilylation reaction and C) an iridium complex catalyst. The method can be used to produce a compound of formula (I). This compound can be used in a hydrosilylation reaction with a vinyl-functional polyorganosiloxane. The resulting product includes an ethyltrimethoxysilyl functional polyorganosiloxane useful in condensation reaction curable sealant compositions.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. national stage filing under 35 U.S.C. § 371 of PCT Application No. PCT/US18/039378 filed on 26 Jun. 2018, which claims the benefit of U.S. Provisional Patent Application No. 62/524,637 filed 26 Jun. 2017 under 35 U.S.C. § 119 (e). PCT Application No. PCT/US18/039378 and U.S. Provisional Patent Application No. 62/524,637 are hereby incorporated by reference.

BACKGROUND

In the reaction scheme shown below, hydrosilylation reaction of vinyltrimethoxysilane with 1,1,3,3-tetramethyldisiloxane using a platinum catalyst yields a mixture including the α-adduct branched isomer and β-adduct linear isomer as reaction products.

However, this method suffers from the drawback that selectivity results in a 65/35 mole ratio of β-adduct/α-adduct. In addition, without prompt removal or deactivation of the Pt catalyst, “over hydrosilylation” will occur, leading to side products in which both hydrogen atoms on the hydrogen terminated organosiloxane oligomer have reacted with a vinyltrimethoxysilane molecule, i.e., αα adduct, αβ adduct, βα adduct, and/or ββ adduct. One method for minimizing the formation of these side products is to use a molar excess of 1,1,3,3-tetramethyldisiloxane. However, this method suffers from the drawback of process inefficiency and the need to recover relatively large amounts of unreacted 1,1,3,3-tetramethyldisiloxane.

There is an industry need to provide one or more of the following benefits: 1) minimize the formation of side products due to over hydrosilylation; 2) produce the beta-adduct with high selectivity and high yield; and 3) produce the beta-adduct stable in the presence of catalyst.

BRIEF SUMMARY OF THE INVENTION

A method for selectively preparing a product comprising an alkoxy-functional organohydrogensiloxane oligomer comprises:

1) reacting starting materials comprising:

(A) a polyorganohydrogensiloxane oligomer of unit formula (I): (HR¹ ₂SiO_(1/2))_(e)(R¹ ₃SiO_(1/2))_(f)(HR¹SiO_(2/2))_(g)(R¹ ₂SiO_(2/2))_(h)(R¹SiO_(3/2))_(i)(HSiO_(3/2))_(j)(SiO_(4/2))_(k) where subscripts e, f, g, h, i, j, and k have values such that 5≥e≥0, 5≥f≥0, 10≥g≥0, 5≥h≥0, subscript i is 0 or 1, 5≥j≥0, subscript k is 0 or 1, with the proviso that a quantity (e+g+j)≥2, and a quantity (e+f+g+h+i+j+k)≤50; and each R¹ is independently a monovalent hydrocarbon group of 1 to 18 carbon or a monovalent halogenated hydrocarbon group of 1 to 18 carbon atoms;

(B) an aliphatically unsaturated alkoxysilane of formula (II):

where R¹ is as described above, each R² is independently an aliphatically unsaturated monovalent hydrocarbon group of 2 to 18 carbon atoms, each R³ is independently a monovalent hydrocarbon group of 1 to 18 carbon atoms, subscript c is 0 or 1; and

(C) an iridium complex of formula [Ir(R⁵)_(x)(R⁶)_(y)]_(z), where subscript x is 1 or 2, R⁵ is a 1,5-cyclooctadiene ligand or a 2,5-norbornadiene ligand, subscript y is 0, 1 or 2, R⁶ is a ligand that can be activated at a temperature less than a boiling point of the organohydrogensiloxane oligomer, and subscript z is 1 or 2, thereby preparing the reaction product comprising the alkoxy-functional organohydrogensiloxane oligomer; and optionally 2) isolating the alkoxy-functional organohydrogensiloxane oligomer prepared in step 1).

In step 1), starting material (C) and starting material (B) may be combined and metered into starting material (A).

The alkoxy-functional organohydrogensiloxane oligomer has unit formula (III):

where R¹, R³, and subscripts c, f, h, i, and k are as described above, subscript b is 0 to 2, m>0, and a quantity (m+n+o+p)=(e+g+j), and each D is independently a divalent hydrocarbon group of 2 to 18 carbon atoms, with the proviso that >90 mol % of all D groups produced in step 1) are linear.

The alkoxy-functional organohydrogensiloxane oligomer is useful in a method for preparing a poly-alkoxy functional polyorganosiloxane. The method for preparing the poly-alkoxy functional polyorganosiloxane comprises:

(1) reacting starting materials comprising:

(a) an alkoxy-functional organohydrogensiloxane oligomer described above,

(b) a polyorganosiloxane having, per molecule, an average of at least two aliphatically unsaturated monovalent hydrocarbon groups; and

(c) a hydrosilylation reaction catalyst.

DETAILED DESCRIPTION OF THE INVENTION

The method for selectively preparing a product comprising an alkoxy-functional organohydrogensiloxane oligomer comprises:

1) reacting starting materials comprising:

(A) a polyorganohydrogensiloxane oligomer of unit formula (I): (HR¹ ₂SiO_(1/2))_(e)(R¹ ₃SiO_(1/2))_(f)(HR¹SiO_(2/2))_(g)(R¹ ₂SiO_(2/2))_(h)(R¹SiO_(3/2))_(i)(HSiO_(3/2))_(j)(SiO_(4/2))_(k) where subscripts e, f, g, h, i, j, and k have values such that 5≥e≥0, 5≥f≥0, 10≥g≥0, 5≥h≥0, subscript i is 0 or 1, 5≥j≥0, subscript k is 0 or 1, with the proviso that a quantity (e+g+j)≥2, and a quantity (e+f+g+h+i+j+k)≤50; and each R¹ is independently a monovalent hydrocarbon group of 1 to 18 carbon or a monovalent halogenated hydrocarbon group of 1 to 18 carbon atoms;

(B) an aliphatically unsaturated alkoxysilane of formula (II):

where each R² is independently an aliphatically unsaturated monovalent hydrocarbon group of 2 to 18 carbon atoms, each R³ is independently a monovalent hydrocarbon group of 1 to 18 carbon atoms, subscript c is 0 or 1; and

(C) an iridium complex of formula [Ir(R⁵)_(x)(R⁶)_(y)]_(z), where subscript x is 1 or 2, R⁵ is a 1,5-cyclooctadiene ligand or a 2,5-norbornadiene ligand, subscript y is 0, 1 or 2, R⁶ is a ligand that can be activated at a temperature less than a boiling point of the organohydrogensiloxane oligomer, and subscript z is 1 or 2, thereby preparing the reaction product comprising the alkoxy-functional organohydrogensiloxane oligomer; and optionally 2) isolating the alkoxy-functional organohydrogensiloxane oligomer prepared in step 1).

Ingredient (A) useful in the method described above is a polyorganohydrogensiloxane oligomer of unit formula (III): (HR¹ ₂SiO_(1/2))_(e)(R¹ ₃SiO_(1/2))_(f)(HR¹SiO_(2/2))_(g)(R¹ ₂SiO_(2/2))_(h)(R¹SiO_(3/2))_(i)(HSiO_(3/2))_(j)(SiO_(4/2))_(k) where subscripts e, f, g, h, i, j, and k have values such that 5≥e≥0, 5≥f≥0, 10≥g≥0, 5≥h≥0, subscript i is 0 or 1, 5≥j≥0, subscript k is 0 or 1, with the proviso that a quantity (e+g+j)≥2, and a quantity (e+f+g+h+i+j+k)≤50; and each R¹ is independently a monovalent hydrocarbon group of 1 to 18 carbon or a monovalent halogenated hydrocarbon group of 1 to 18 carbon atoms. Alternatively, monovalent hydrocarbon groups for R¹ have 1 to 12 carbon atoms, and alternatively 1 to 10 carbon atoms.

Suitable monovalent hydrocarbon groups for R¹ include, but are not limited to, an alkyl group of 1 to 6 carbon atoms and an aryl group of 6 to 10 carbon atoms. Suitable alkyl groups for R¹ are exemplified by, but not limited to, methyl, ethyl, propyl (e.g., iso-propyl and/or n-propyl), butyl (e.g., isobutyl, n-butyl, tert-butyl, and/or sec-butyl), pentyl (e.g., isopentyl, neopentyl, and/or tert-pentyl), hexyl, as well as branched saturated hydrocarbon groups of 6 carbon atoms. Suitable aryl groups for R¹ are exemplified by, but not limited to, phenyl, tolyl, xylyl, naphthyl, benzyl, and dimethyl phenyl. Suitable monovalent halogenated hydrocarbon groups for R¹ include, but are not limited to, a halogenated alkyl group of 1 to 6 carbon atoms, or a halogenated aryl group of 6 to 10 carbon atoms. Suitable halogenated alkyl groups for R¹ are exemplified by, but not limited to, the alkyl groups described above where one or more hydrogen atoms is replaced with a halogen atom, such as F or Cl. For example, fluoromethyl, 2-fluoropropyl, 3,3,3-trifluoropropyl, 4,4,4-trifluorobutyl, 4,4,4,3,3-pentafluorobutyl, 5,5,5,4,4,3,3-heptafluoropentyl, 6,6,6,5,5,4,4,3,3-nonafluorohexyl, and 8,8,8,7,7-pentafluorooctyl, 2,2-difluorocyclopropyl, 2,3-difluorocyclobutyl, 3,4-difluorocyclohexyl, and 3,4-difluoro-5-methylcycloheptyl, chloromethyl, chloropropyl, 2-dichlorocyclopropyl, and 2,3-dichlorocyclopentyl are examples of suitable halogenated alkyl groups. Suitable halogenated aryl groups for R¹ are exemplified by, but not limited to, the aryl groups described above where one or more hydrogen atoms is replaced with a halogen atom, such as F or Cl. For example, chlorobenzyl and fluorobenzyl are suitable halogenated aryl groups. Alternatively, each R¹ is independently methyl, ethyl or propyl. Each instance of R¹ may be the same or different. Alternatively, each R¹ is a methyl group. Examples of suitable hydridosilanes include trimethylsilane and trimethoxysilane.

In an alternative embodiment, ingredient (A) is an α,γ-hydrogen terminated organohydrogensiloxane oligomer of formula (IV):

where each R¹ is independently an alkyl group of 1 to 6 carbon atoms, an aryl group of 6 to 10 carbon atoms, a halogenated alkyl group of 1 to 6 carbon atoms, or a halogenated aryl group of 6 to 10 carbon atoms; and subscript a is an integer up to 20. Alternatively, subscript a is 0 to 20, alternatively subscript a is 0 to 10; alternatively subscript a is 0 to 5; and alternatively subscript a is 0 or 1. Alternatively, subscript a may be 2 to 10; alternatively subscript a is 2 to 5. Examples of suitable organohydrogensiloxane oligomers include 1,1,3,3,5,5-hexamethyltrisiloxane, 1,1,3,3-tetramethyldisiloxane, 1,1,3,3,5,5-hexaethyltrisiloxane, and 1,1,3,3-tetraethyldisiloxane. Alternatively, ingredient (A) may be 1,1,3,3-tetramethyldisiloxane.

When the organohydrogensiloxane oligomer of formula (IV) is used in the method, the product comprises an alkoxy-functional organohydrogensiloxane oligomer produced of formula (V):

where R¹ and subscripts a and c are as described above, D is a divalent hydrocarbon group of 2 to 18 carbon atoms, with the proviso that >90 mol % of D are linear divalent hydrocarbon groups.

In an alternative embodiment, ingredient (A) the organohydrogensiloxane oligomer has unit formula (VI): (HR¹ ₂SiO_(1/2))₃(R¹ ₂SiO_(2/2))_(q)(R¹SiO_(3/2)), where subscript q is 0 to 3. The polyorganohydrogensiloxane oligomer of this unit formula may have formula (VII):

where R¹ is as described above. Examples of such organohydrogensiloxane oligomers include siloxanes of formula (Me₂HSiO_(1/2))₃(PrSiO_(3/2)), where Me represents a methyl group and Pr represents a propyl group.

When the organohydrogensiloxane oligomer used for ingredient A) in the method described above has unit formula (VI) or (VII), the product may comprise an alkoxy-functional organohydrogensiloxane oligomer of formula (VIIIa), formula (VIIIb), or both, where formula (VIIIa) is:

and formula (VIIIb) is:

where R¹ and subscript c are as described above, each D is independently a divalent hydrocarbon group of 2 to 18 carbon atoms, with the proviso that >90 mol % of D are linear divalent hydrocarbon groups.

In an alternative embodiment of the invention, ingredient (A) the organohydrogensiloxane oligomer may have unit formula (IX): (HR¹ ₂SiO_(1/2))₂(R¹ ₂SiO_(2/2))_(q)(HR¹SiO_(2/2))_(r), where R¹ is as described above, subscript q is 0 to 3, and subscript r is 0 to 3. In this embodiment, the organohydrogensiloxane oligomer may have formula (X):

where R¹ is as described above. Examples of such organohydrogensiloxane oligomers include 1,1,3,5,5-pentamethyltrisiloxane. In this embodiment, the product comprises an alkoxy-functional organohydrogensiloxane oligomer of formula (XI), formula (XII), or a combination thereof, where formula (XI) is

and formula (XII) is

where R¹ and subscript c are as described above.

In an alternative embodiment ingredient (A) the organohydrogensiloxane oligomer is cyclic. The cyclic organohydrogensiloxane oligomer may have unit formula: (R¹ ₂SiO_(2/2))_(v)(R¹HSiO_(2/2))_(s), where R¹ is as described above, subscript s≥3, and subscript v≥0. Alternatively, subscript s may be 3 to 14; alternatively 3 to 9, alternatively 3 to 6, alternatively 3 to 5, and alternatively 4. Alternatively, subscript v may be 0 to 14; alternatively 0 to 9, alternatively 0 to 6, alternatively 0 to 5, and alternatively 0. When this cyclic organohydrogensiloxane oligomer is used as ingredient (A), then the product may comprise an alkoxy-functional organohydrogensiloxane oligomer of unit formula (XIII): (R¹ ₂SiO_(2/2))_(v)(R¹HSiO_(2/2))_(t)

where R, R¹, D, and subscripts c and v are as described above, subscript t is 0 or more, subscript u is 1 or more, and a quantity (t+u)=s.

Ingredient (B) useful in the method described above is an aliphatically unsaturated alkoxysilane of formula (XIV): R¹ _(d)R²Si(OR³)_((3−d)), where each R¹ is independently a monovalent hydrocarbon group or a monovalent halogenated hydrocarbon group (as described above), each R² is independently an aliphatically unsaturated hydrocarbon group, each R³ is independently a monovalent hydrocarbon group, subscript d is 0 or 1. The aliphatically unsaturated hydrocarbon group for R² may be an alkenyl group or an alkynyl group. Suitable alkenyl groups include vinyl, allyl, propenyl, butenyl and hexenyl; alternatively vinyl, allyl or hexenyl; and alternatively vinyl. The monovalent hydrocarbon group for R³ may be a monovalent hydrocarbon group as described above for R¹.

Ingredient (B) may comprise an aliphatically unsaturated alkoxysilane exemplified by a dialkoxysilane, such as a dialkenyldialkoxysilane; a trialkoxysilane, such as an alkenyltrialkoxysilane; or a combination thereof. Examples of suitable aliphatically unsaturated alkoxysilanes include vinyltrimethoxysilane, allyltriethoxysilane, allyltrimethoxysilane, vinyltriethoxysilane, hexenyltrimethoxysilane, vinylmethyldimethoxysilane, hexenylmethyldimethoxysilane, hexenyltriethoxysilane, and a combination thereof, and alternatively vinyltrimethoxysilane.

Ingredient (A) and ingredient (B) are present in relative molar amounts of ingredient (A):ingredient (B) of 1:1 to >1:1, alternatively greater than or equal to 1, i.e., (A):(B) ratio ≥1:1. Alternatively, (A):(B) ratio may range from 5:1 to 1:1, alternatively 2:1 to 1:1; and alternatively 1.5:1 to 1:1. Without wishing to be bound by theory, it is thought that a molar excess of ingredient (A) relative to ingredient (B) may favorably affect yield in the product.

Ingredient (C) useful in the method and composition described herein is an iridium complex. The iridium complex has formula (XV): [Ir(R⁵)_(x)(R⁶)_(y)]_(z), where subscript x is 1 or 2, R⁵ is a 1,5-cyclooctadiene ligand or a 2,5-norbornadiene ligand, subscript y is 0 to 2, alternatively 0 or 1, R⁶ is a ligand that can be activated, and subscript z is 1 or 2. Alternatively, subscript z=2. Activating with respect to R⁶ may be performed by any convenient means, such as heating at a temperature less than the boiling point of the organohydrogensiloxane oligomer, adding a silver salt, or by photochemical or electrochemical means in step (1) of the method described herein. R⁶ may be an anionic ligand. Examples of ligands suitable for R⁶ include a halogen atom, a beta-ketoester ligand, a halogenated beta-ketoester ligand, an alkoxy ligand, a cyanoalkyl ligand, an aryl ligand, and a heteroaryl ligand. Examples of suitable halogen atoms include bromine (Br), chlorine (Cl) and iodine (I). Alternatively, the halogen atom may be Cl. Examples of beta-ketoester ligands include acetyl acetonate (acac). Examples of halogenated beta-ketoesters include hexafluoro acetylacetonate (hfacac). Examples of alkoxy ligands include methoxy, ethoxy, and propoxy. Alternatively the alkoxy ligand may be methoxy. Examples of suitable cyanoalkyl ligands include CH₃CN, acetonitrile, and tetrahydrofuran (THF). Examples of suitable aryl ligands include phenyl, benzyl, or indenyl. Examples of suitable heteroaryl ligands include pyridine.

Examples suitable catalysts for ingredient (C) include, but are not limited to [Ir(I)CODCl-dimer, Ir(I)CODacac, Ir(I)COD₂BARF, Ir(I)COD(OMe)-dimer, Ir(I)COD(hfacac), Ir(I)COD(CH₃CN)₂, Ir(I)COD(pyridine), Ir(I)COD(indenyl), and mixtures thereof; wherein COD represents a 1,5-cyclooctadiene group, BARF represents tetrakis(3,5-bis(trifluoromethyl)phenyl)borate, acac represents acetyl acetonate, and hfacac represents hexafluoro acetylacetonate.

The amount of ingredient (C) used in step (1) of the method described above depends on various factors including the specific organohydrogensiloxane oligomer selected for ingredient (A), the specific alkoxysilane selected for ingredient (B), and the temperature to which the mixture can be heated without boiling away the organohydrogensiloxane oligomer selected for ingredient (A). However, the amount of ingredient (C) may be sufficient to provide a molar amount of iridium metal of 1 parts per million (ppm) to 100 ppm, alternatively 5 ppm to 80 ppm, alternatively 5 ppm to 20 ppm based on combined weights of ingredients (A) and (B). The method may optionally further comprise deactivation or removal of the catalyst. However, with appropriate catalyst loading, the step of deactivation or removal of the catalyst may be omitted.

The method described herein may be performed at 1 atmosphere of pressure or higher. Alternatively, the method may be performed at 1 atmosphere to 1.5 atmosphere. Step 1) may be performed at 0° C. to 150° C., alternatively 50° C. to 150° C., alternatively 60° C. to 150° C., and alternatively 50° C. to 100° C. The temperature for heating in step 1) depends on various factors including the pressure selected, however, heating may be performed at least 70° C. to ensure the reaction proceeds quickly enough to be practical. The upper limit for temperature during heating is not critical and depends on the ingredients selected, i.e., the upper limit should be such that the ingredients do not vaporize out of the reactor selected for performing the method. Alternatively, heating may be from 70° C. to 150° C., alternatively 70° C. to 100° C.

Step (1) of the method described above produces a product comprising an alkoxy-functional organohydrogensiloxane oligomer. The alkoxy-functional organohydrogensiloxane oligomer has unit formula (XVI):

where R¹, R³, and subscripts c, f, h, i, and k are as described above, subscript b is 0 to 2, subscript m>0, and subscripts m, n, o, and p have values such that a quantity (m+n+o+p)=(e+g+j), and each D is independently a divalent hydrocarbon group of 2 to 18 carbon atoms, with the proviso that >90 mol % of all D groups produced in step 1) are linear. Subscripts e, g, and j are as described above in formula (I). The method described herein provides the benefit that this alkoxy-functional organohydrogensiloxane oligomer is produced with high selectivity to the β-adduct compound, i.e., where D is linear, with either none or lower amounts of the corresponding α-adduct compound than existing methods using other catalysts.

The ingredients in step 1) of the method described above form a mixture, which may be homogeneous or heterogeneous. Alternatively, ingredients comprising (B) and (C) may be combined, e.g., by mixing and the resulting mixture comprising ingredients (B) and (C) may be gradually added into ingredients comprising (A). One or more additional ingredients, i.e., in addition to ingredients (A), (B), and (C) described above, may optionally be used in the method and composition described herein. The additional ingredient, when present, may be (D) a solvent or (E) a stabilizer, or both (D) and (E).

Ingredient (D) is a solvent that may be added to the mixture used in step 1) of the method described herein. One or more of ingredients (A), (B), and/or (C) may be provided in a solvent. For example, ingredient (C) may be dissolved in a solvent that is added to a mixture of ingredients (A) and (B) in step 1). Alternatively, ingredients (B) and (C) may be combined with a solvent, and the resulting solution gradually metered into a vessel containing ingredient (A), optionally mixed with solvent. The solvent for ingredients (B) and (C) and the solvent for ingredient (A) may be the same or different. The solvent may facilitate contacting of reactants and catalyst, flow of the mixture and/or introduction of certain ingredients, such as the catalyst. Solvents used herein are those that help fluidize the ingredients of the mixture but essentially do not react with any of these ingredients. Solvents may be selected based on solubility the ingredients in the mixture and volatility. The solubility refers to the solvent being sufficient to dissolve ingredients of the mixture. Volatility refers to vapor pressure of the solvent. If the solvent is too volatile (having too high vapor pressure) the solvent may not remain in solution during heating. However, if the solvent is not volatile enough (too low vapor pressure) the solvent may be difficult to remove from the product or isolate from the alkoxy-functional organohydrogensiloxane oligomer.

The solvent may be an organic solvent. The organic solvent can be an aromatic hydrocarbon such as benzene, toluene, or xylene, or a combination thereof. Ingredient (D) may be one solvent. Alternatively, ingredient (D) may comprise two or more different solvents.

The amount of solvent can depend on various factors including the specific solvent selected and the amount and type of other ingredients selected for the mixture. However, the amount of solvent may range from 0% to 99%, or when present, 1% to 99%, and alternatively 2% to 50%, based on the weight of the mixture.

Starting material (E), the stabilizer may be an oxidant, a diene, or a polyene. Step 1) may optionally be performed in the presence of an oxidant, such as oxygen gas (O₂), an organic oxidant such as a quinone, or an inorganic oxidant such as an oxide (as described, for example, in DE102005030581). Alternatively, the stabilizer may be a diene or polyene added in excess to further stabilize the Ir catalyst to allow better overall performance (as described, for example in WO 2008107332 A1, EP1156052 B1, EP1633761 B1, EP1201671 B1, DE10232663 C1).

The method may optionally further comprise one or more additional steps. The method may further comprise a step of: recovering a fraction containing the alkoxy-functional organohydrogensiloxane oligomer from the product. Because the alkoxy-functional organohydrogensiloxane oligomer may comprise a β-adduct compound (i.e., where D is linear) and a corresponding α-adduct compound (i.e., where D is not linear) are difficult and/or costly to separate from one another, a fraction comprising both β-adduct compound and α-adduct compound may be recovered from the product after step 1) described above. It is desirable that this fraction contain >90% β-adduct compound, alternatively >90% to 100% β-adduct compound, alternatively 92% to 100%, alternatively >90% to <100%, alternatively 92% to <100%, and alternatively 95% to <100% β-adduct compound, based on the combined amounts of β-adduct compound and α-adduct compound in the fraction. Recovering this fraction may be performed by any convenient means, such as stripping or distillation, with heating or under vacuum, or a combination thereof.

The fraction described above comprising the β-adduct compound alkoxy-functional organohydrogensiloxane oligomer above is useful for functionalization of polyorganosiloxanes, including oligomers and longer chain polymers, containing aliphatically unsaturated functionality. For example, a hydrosilylation reaction of the SiH group in the alkoxy-functional organohydrogensiloxane oligomer of formula (X) with an aliphatically unsaturated group bonded to silicon in a polyorganosiloxane (such as a polydiorganosiloxane having aliphatically unsaturated terminal groups) can produce an alkoxy-functional polyorganosiloxane. The polyorganosiloxane having aliphatically unsaturated terminal groups may have unit formula (XVII): (R⁷R₈SiO_(1/2))_(e)(R⁷R₈SiO_(2/2))_(f)(R⁷SiO_(3/2))_(g)(SiO_(4/2))_(h), where each R⁷ is independently a hydrogen atom, an alkyl group, an aryl group, a halogenated alkyl group, or a halogenated aryl group (such as those described above for R¹), and each R⁸ is independently an aliphatically unsaturated hydrocarbon group such as an alkenyl group exemplified by alkenyl groups such as vinyl, allyl, butenyl, and hexenyl; and alkynyl groups such as ethynyl and propynyl. Subscript e is an integer of 0 or more, subscript f is an integer of 0 or more, subscript g is an integer of 0 or more, and subscript h is an integer of 0 or more, with the proviso that a quantity (f+g)≥1. Alternatively, the polyorganosiloxane may be a polydiorganosiloxane. The polydiorganosiloxane having aliphatically unsaturated terminal groups may have formula (XVIII): R⁷ ₂R⁸SiO(R⁷ ₂SiO)_(d)SiR⁷ ₂R⁸.

In formula (XVIII), R⁷ and R⁸ are as described above. Subscript d may be 0 or a positive number. Alternatively, each R⁷ may be an alkyl group or an aryl group as described above for R¹. Alternatively, subscript d has an average value of at least 2. Alternatively subscript d may have a value ranging from 2 to 2000.

The compound of formula (XIX) may comprise a polydiorganosiloxane such as i) dimethylvinylsiloxy-terminated polydimethylsiloxane, ii) dimethylvinylsiloxy-terminated poly(dimethylsiloxane/methylphenylsiloxane), iii) dimethylvinylsiloxy-terminated poly(dimethylsiloxane/diphenylsiloxane), iv) phenyl, methyl, vinyl-siloxy-terminated polydimethylsiloxane, or v) dimethylhexenylsiloxy-terminated polydimethylsiloxane.

The alkoxy-functional polyorganosiloxane may be produced by combining the product or fraction including the β-adduct compound alkoxy-functional organohydrogensiloxane oligomer with a polydiorganosiloxane of formula (XIX) as described above.

The hydrosilylation reaction to prepare the alkoxy-functional polyorganosiloxane may be performed by a method comprising:

combining starting materials comprising

(a) the product (or fraction) comprising the β-adduct compound alkoxy-functional organohydrogensiloxane oligomer as described above,

(b) the polyorganosiloxane having at least one aliphatically unsaturated silicon bonded group per molecule as described above, and

(c) a hydrosilylation catalyst other than the iridium complex described above. Suitable catalysts for catalyzing hydrosilylation reaction are known in the art and are commercially available. Such hydrosilylation catalysts can be a platinum group metal, such as platinum. Alternatively, the hydrosilylation catalyst may be a compound of such a metal, for example, chloroplatinic acid, chloroplatinic acid hexahydrate, platinum dichloride, and complexes of said compounds with low molecular weight organopolysiloxanes or platinum compounds microencapsulated in a matrix or core/shell type structure. Complexes of platinum with low molecular weight organopolysiloxanes include 1,3-diethenyl-1,1,3,3-tetramethyldisiloxane complexes with platinum. These complexes may be microencapsulated in a resin matrix. Exemplary hydrosilylation catalysts are described in U.S. Pat. Nos. 3,159,601; 3,220,972; 3,296,291; 3,419,593; 3,516,946; 3,814,730; 3,989,668; 4,784,879; 5,036,117; and 5,175,325 and EP 0 347 895 B. Microencapsulated hydrosilylation catalysts and methods of preparing them are known in the art, as exemplified in U.S. Pat. Nos. 4,766,176 and 5,017,654. Combining the starting materials may be performed at elevated temperature, such as heating at 50° C. to 250° C.

The polyalkoxy-functional polyorganosiloxanes produced by the hydrosilylation of described above may have formula: (XX): R⁷ ₂R¹¹SiO(R⁷ ₂SiO)_(d)SiR⁷ ₂R¹¹, where R⁷ and subscript d are as described above, and each R¹¹ is polyalkoxy functional group, with the proviso that >90 mol % of R¹¹ are β-adduct. Alternatively, in formula (XIII), >90 mol % to 100 mol % of R¹¹ are β-adduct groups. Alternatively, in formula (XIII), 92% to <100% % of R¹¹ are β-adduct groups.

For example, when (b) the polyorganosiloxane having aliphatically unsaturated terminal groups is a polydiorganosiloxane of formula (XIV):

where subscript n is 1 to 2,000; the poly-alkoxy functional polyorganosiloxane may have formula (XXI):

where each D¹ is independently a divalent hydrocarbon group; where R¹, R², D and subscript c are as described above.

Alternatively, the poly-alkoxy functional polyorganosiloxane may have formula (XXII):

where each D¹ is independently a divalent hydrocarbon group; where R¹, R², D and subscript c are as described above.

The poly-alkoxy functional polyorganosiloxanes, such as polyalkoxy-functional polydimethylsiloxanes, prepared as described above can be used in any application that utilizes reactivity of the alkoxy groups.

For example, the poly-alkoxy functional polyorganosiloxane prepared as described above is useful in condensation reaction curable compositions, such as sealant compositions. Suitable condensation reaction curable compositions can be prepared by mixing starting materials comprising:

(i) the poly-alkoxy functional polyorganosiloxane prepared as described above, and

(ii) condensation reaction catalyst. Without wishing to be bound by theory, it thought that a condensation reaction curable composition including (i) the poly-alkoxy functional polyorganosiloxane will cure faster than a similar condensation reaction curable composition containing a different poly-alkoxy functional polyorganosiloxane (prepared using a conventional endblocker having higher branched isomer content).

Starting material (ii) is a condensation reaction catalyst. Suitable condensation reaction catalysts include tin catalysts and titanium catalysts. Suitable tin catalysts include organotin compounds where the valence of the tin is either +4 or +2, i.e., Tin (IV) compounds or Tin (II) compounds. Examples of tin (IV) compounds include stannic salts of carboxylic acids such as dibutyl tin dilaurate, dimethyl tin dilaurate, di-(n-butyl)tin bis-ketonate, dibutyl tin diacetate, dibutyl tin maleate, dibutyl tin diacetylacetonate, dibutyl tin dimethoxide, carbomethoxyphenyl tin tris-uberate, dibutyl tin dioctanoate, dibutyl tin diformate, isobutyl tin triceroate, dimethyl tin dibutyrate, dimethyl tin di-neodeconoate, dibutyl tin di-neodeconoate, triethyl tin tartrate, dibutyl tin dibenzoate, butyltintri-2-ethylhexanoate, dioctyl tin diacetate, tin octylate, tin oleate, tin butyrate, tin naphthenate, dimethyl tin dichloride, a combination thereof, and/or a partial hydrolysis product thereof. Tin (IV) compounds are known in the art and are commercially available, such as Metatin® 740 and Fascat® 4202 from Acima Specialty Chemicals of Switzerland, Europe, which is a business unit of The Dow Chemical Company. Examples of tin (II) compounds include tin (II) salts of organic carboxylic acids such as tin (II) diacetate, tin (II) dioctanoate, tin (II) diethylhexanoate, tin (II) dilaurate, stannous salts of carboxylic acids such as stannous octoate, stannous oleate, stannous acetate, stannous laurate, stannous stearate, stannous naphthanate, stannous hexanoate, stannous succinate, stannous caprylate, and a combination thereof. Exemplary titanium catalysts include titanium esters such as tetra-n-butyltitanate tetraisopropyltitanate, tetra-2-ethylhexyltitanate, tetraphenyltitanate, triethanolamine titanate, organosiloxytitanium compounds, and dicarbonyl titanium compounds, such as titanium ethyl acetoacetate and bis(acetoacetonyl)-diisopropoxy titanium (IV). A titanium catalyst may be used when the composition will be formulated as a room temperature vulcanizing sealant composition. The amount of condensation reaction catalyst depends on various factors including the amount of starting material (i) and the types and amounts of any additional starting materials added to the composition, however the amount of condensation reaction catalyst may be 0.2 to 6, alternatively 0.5 to 3, parts by weight based on the weight of starting material (i).

The condensation reaction curable composition may further comprise one or more additional ingredients distinct from ingredients (i) and (ii). Suitable additional ingredients are exemplified by (iii) a filler; (iv) a filler treating agent; (v) a crosslinker; (vi) a surface modifier, (vii) a drying agent; (viii) an extender, a plasticizer, or a combination thereof; (ix) a biocide; (x) a flame retardant; (xi) a chain lengthener; (xii) an endblocker; (xiii) a nonreactive binder; (xiv) an anti-aging additive; (xv) a water release agent; (xvi) a pigment; (xvii) a rheological additive; (xviii) a vehicle (such as a solvent and/or a diluent); (xix) a tackifying agent; (xx) a corrosion inhibitor; and a combination of two or more thereof. These additional ingredients and their amounts for use in a condensation reaction curable composition are exemplified by those disclosed, for example, in U.S. Pat. No. 9,156,948.

Starting material (iii) that may be added to the composition is a filler. The filler may comprise a reinforcing filler, an extending filler, or a combination thereof. For example, the composition may optionally further comprise ingredient (iii-1), a reinforcing filler, which when present may be added in an amount ranging from 0.1% to 95%, alternatively 1% to 60%, based on the weight of the composition. The exact amount of starting material (iii-1) depends on various factors including the form of the reaction product of the composition and whether any other fillers are added. Examples of suitable reinforcing fillers include precipitated calcium carbonates and reinforcing silica fillers such as fume silica, silica aerogel, silica xerogel, and precipitated silica. Suitable precipitated calcium carbonates include Winnofil® SPM from Solvay and Ultrapflex® and Ultrapflex® 100 from Specialty Minerals, Inc. Fumed silicas are known in the art and commercially available; e.g., fumed silica sold under the name CAB-O-SIL by Cabot Corporation of Massachusetts, U.S.A.

The composition may optionally further comprise starting material (iii-2) an extending filler in an amount ranging from 0.1% to 95%, alternatively 1% to 60%, and alternatively 1% to 20%, based on the weight of the composition. Examples of extending fillers include crushed quartz, aluminum oxide, magnesium oxide, calcium carbonate such as ground calcium carbonate, precipitated calcium carbonate, zinc oxide, talc, diatomaceous earth, iron oxide, clays, mica, chalk, titanium dioxide, zirconia, sand, carbon black, graphite, or a combination thereof. Extending fillers are known in the art and commercially available; such as a ground quartz sold under the name MIN-U-SIL by U.S. Silica of Berkeley Springs, W. Va. Examples of extending calcium carbonates include CS-11 from Imerys, G3T from Huber, and Omyacarb 2T from Omya.

The composition may optionally further comprise starting material (iv) a treating agent. The amount of starting material (iv) can vary depending on factors such as the type of treating agent selected and the type and amount of particulates to be treated, and whether the particulates are treated before being added to the composition, or whether the particulates are treated in situ. However, starting material (iv) may be used in an amount ranging from 0.01% to 20%, alternatively 0.1% to 15%, and alternatively 0.5% to 5%, based on the weight of the composition. Particulates, such as the filler, the physical drying agent, certain flame retardants, certain pigments, and/or certain water release agents, when present, may optionally be surface treated with starting material (iv). Particulates may be treated with starting material (iv) before being added to the composition, or in situ. Starting material (iv) may comprise an alkoxysilane, an alkoxy-functional oligosiloxane, a cyclic polyorganosiloxane, a hydroxyl-functional oligosiloxane such as a dimethyl siloxane or methyl phenyl siloxane, or a fatty acid. Examples of fatty acids include stearates such as calcium stearate.

Some representative organosilicon filler treating agents that can be used as starting material (iv) include compositions normally used to treat silica fillers such as organochlorosilanes, organosiloxanes, organodisilazanes such as hexaalkyl disilazane, and organoalkoxysilanes such as C₆H₁₃Si(OCH₃)₃, C₈H₁₇Si(OC₂H₅)₃, C₁₀H₂₁Si(OCH₃)₃, C₁₂H₂₅Si(OCH₃)₃, C₁₄H₂₉Si(OC₂H₅)₃, and C₆H₅CH₂CH₂Si(OCH₃)₃. Other treating agents that can be used include alkylthiols, fatty acids, titanates, titanate coupling agents, zirconate coupling agents, and combinations thereof.

Alternatively, starting material (iv) may comprise an alkoxysilane having the formula (XXIII): R¹³ _(p)Si(OR¹⁴)_((4−p)), where subscript p may have a value ranging from 1 to 3, alternatively subscript p is 3. Each R¹³ is independently a monovalent organic group, such as a monovalent hydrocarbon group of 1 to 50 carbon atoms, alternatively 8 to 30 carbon atoms, alternatively 8 to 18 carbon atoms. R¹³ is exemplified by alkyl groups such as hexyl, octyl, dodecyl, tetradecyl, hexadecyl, and octadecyl; and aromatic groups such as benzyl and phenylethyl. R¹³ may be saturated or unsaturated, and branched or unbranched. Alternatively, R¹³ may be saturated and unbranched.

Each R¹⁴ is independently a saturated hydrocarbon group of 1 to 4 carbon atoms, alternatively 1 to 2 carbon atoms. Starting material (iv) is exemplified by hexyltrimethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, tetradecyltrimethoxysilane, phenylethyltrimethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, and combinations thereof.

Alkoxy-functional oligosiloxanes may also be used as treating agents. For example, suitable alkoxy-functional oligosiloxanes include those of the formula (XXIX): (R¹⁵O)_(q)Si(OSiR¹⁶ ₂R¹⁷)_((4−q)). In this formula, subscript q is 1, 2 or 3, alternatively subscript q is 3. Each R¹⁵ may be an alkyl group. Each R¹⁶ may be an unsaturated monovalent hydrocarbon group of 1 to 10 carbon atoms. Each R¹⁷ may be an unsaturated monovalent hydrocarbon group having at least 10 carbon atoms.

Alternatively, a polyorganosiloxane capable of hydrogen bonding is useful as a treating agent. This strategy to treating surface of a filler takes advantage of multiple hydrogen bonds, either clustered or dispersed or both, as the means to tether the compatibilization moiety to the filler surface. The polyorganosiloxane capable of hydrogen bonding has an average, per molecule, of at least one silicon-bonded group capable of hydrogen bonding. The group may be selected from: an organic group having multiple hydroxyl functionalities or an organic group having at least one amino functional group. The polyorganosiloxane capable of hydrogen bonding means that hydrogen bonding is the primary mode of attachment for the polyorganosiloxane to a filler. The polyorganosiloxane may be incapable of forming covalent bonds with the filler. The polyorganosiloxane may be free of condensable silyl groups e.g., silicon bonded alkoxy groups, silazanes, and silanols. The polyorganosiloxane capable of hydrogen bonding may be selected from the group consisting of a saccharide-siloxane polymer, an amino-functional polyorganosiloxane, and a combination thereof. Alternatively, the polyorganosiloxane capable of hydrogen bonding may be a saccharide-siloxane polymer.

Starting material (v) is a crosslinker. Starting material (v) may comprise a silane crosslinker having hydrolyzable groups or partial or full hydrolysis products thereof. Starting material (v) has an average, per molecule, of greater than two substituents reactive with the alkoxy groups on starting material (i). Examples of suitable silane crosslinkers for starting material (v) may have general formula (XXX): R¹⁰ _(k)Si(R⁹)_((4−k)), where each R¹⁰ is independently a monovalent hydrocarbon group such as an alkyl group; each R⁹ is a hydrolyzable substituent, for example, a halogen atom, an acetamido group, an acyloxy group such as acetoxy, an alkoxy group, an amido group, an amino group, an aminoxy group, a hydroxyl group, an oximo group, a ketoximo group, or a methylacetamido group; and each instance of subscript k may be 0, 1, 2, or 3. For starting material (v), subscript k has an average value greater than 2. Alternatively, subscript k may have a value ranging from 3 to 4. Alternatively, each R⁹ may be independently selected from hydroxyl, alkoxy, acetoxy, amide, or oxime. Alternatively, starting material (v) may be selected from an acyloxysilane, an alkoxysilane, a ketoximosilane, and an oximosilane.

Starting material (v) may comprise an alkoxysilane exemplified by a dialkoxysilane, such as a dialkyldialkoxysilane; a trialkoxysilane, such as an alkyltrialkoxysilane; a tetraalkoxysilane; or partial or full hydrolysis products thereof, or another combination thereof. Examples of suitable trialkoxysilanes include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, and a combination thereof, and alternatively methyltrimethoxysilane. Examples of suitable tetraalkoxysilanes include tetraethoxysilane. The amount of the alkoxysilane that is used in the composition may range from 0.5 to 15, parts by weight per 100 parts by weight of starting material (i).

Starting material (v) may comprise an acyloxysilane, such as an acetoxysilane. Acetoxysilanes include a tetraacetoxysilane, an organotriacetoxysilane, a diorganodiacetoxysilane, or a combination thereof. The acetoxysilane may contain alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, and tertiary butyl; alkenyl groups such as vinyl, allyl, or hexenyl; aryl groups such as phenyl, tolyl, or xylyl; aralkyl groups such as benzyl or 2-phenylethyl; and fluorinated alkyl groups such as 3,3,3-trifluoropropyl. Exemplary acetoxysilanes include, but are not limited to, tetraacetoxysilane, methyltriacetoxysilane, ethyltriacetoxysilane, vinyltriacetoxysilane, propyltriacetoxysi lane, butyltriacetoxysi lane, phenyltriacetoxysilane, octyltriacetoxysilane, dimethyldiacetoxysilane, phenylmethyldiacetoxysilane, vinylmethyldiacetoxysilane, diphenyl diacetoxysilane, tetraacetoxysilane, and combinations thereof. Alternatively, starting material (v) may comprise organotriacetoxysilanes, for example mixtures comprising methyltriacetoxysilane and ethyltriacetoxysilane. The amount of the acetoxysilane that is used in the curable silicone composition may range from 0.5 to 15 parts by weight per 100 parts by weight of starting material (i); alternatively 3 to 10 parts by weight of acetoxysilane per 100 parts by weight of starting material (i).

Examples of silanes suitable for starting material (v) containing both alkoxy and acetoxy groups that may be used in the composition include methyldiacetoxymethoxysilane, methylacetoxydimethoxysilane, vinyldiacetoxymethoxysilane, vinylacetoxydimethoxysilane, methyldiacetoxyethoxysilane, metylacetoxydiethoxysilane, and combinations thereof.

Aminofunctional alkoxysilanes suitable for starting material (v) are exemplified by H₂N(CH₂)₂Si(OCH₃)₃, H₂N(CH₂)₂Si(OCH₂CH₃)₃, H₂N(CH₂)₃Si(OCH₃)₃, H₂N(CH₂)₃Si(OCH₂CH₃)₃, CH₃NH(CH₂)₃Si(OCH₃)₃, CH₃NH(CH₂)₃Si(OCH₂CH₃)₃, CH₃NH(CH₂)₅Si(OCH₃)₃, CH₃NH(CH₂)₅Si(OCH₂CH₃)₃, H₂N(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, H₂N(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃, CH₃NH(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, CH₃NH(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃, C₄H₉NH(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, C₄H₉NH(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃, H₂N(CH₂)₂SiCH₃(OCH₃)₂, H₂N(CH₂)₂SiCH₃(OCH₂CH₃)₂, H₂N(CH₂)₃SiCH₃(OCH₃)₂, H₂N(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₃SiCH₃(OCH₃)₂, CH₃NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₅SiCH₃(OCH₃)₂, CH₃NH(CH₂)₅SiCH₃(OCH₂CH₃)₂, H₂N(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂, H₂N(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂, CH₃NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, C₄H₉NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂, C₄H₉NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, and a combination thereof.

Suitable oximosilanes for starting material (v) include alkyltrioximosilanes such as methyltrioximosilane, ethyltrioximosilane, propyltrioximosilane, and butyltrioximosilane; alkoxytrioximosilanes such as methoxytrioximosilane, ethoxytrioximosilane, and propoxytrioximosilane; or alkenyltrioximosilanes such as propenyltrioximosilane or butenyltrioximosilane; alkenyloximosilanes such as vinyloximosilane; alkenylalkyldioximosilanes such as vinyl methyl dioximosilane, vinyl ethyldioximosilane, vinyl methyldioximosilane, or vinylethyldioximosilane; or combinations thereof.

Suitable ketoximosilanes for starting material (v) include methyl tris(dimethylketoximo)silane, methyl tris(methylethylketoximo)silane, methyl tris(methylpropylketoximo)silane, methyl tris(methylisobutylketoximo)silane, ethyl tris(dimethylketoximo)silane, ethyl tris(methylethylketoximo)silane, ethyl tris(methylpropylketoximo)silane, ethyl tris(methylisobutylketoximo)silane, vinyl tris(dimethylketoximo)silane, vinyl tris(methylethylketoximo)silane, vinyl tris(methylpropylketoximo)silane, vinyl tris(methylisobutylketoximo)silane, tetrakis(dimethylketoximo)silane, tetrakis(methylethylketoximo)silane, tetrakis(methylpropylketoximo)silane, tetrakis(methylisobutylketoximo)silane, methylbis(dimethylketoximo)silane, methylbis(cyclohexylketoximo)silane, triethoxy(ethylmethylketoxime)silane, diethoxydi(ethylmethylketoxime)silane, ethoxytri(ethylmethylketoxime)silane, methylvinylbis(methylisobutylketoximo)silane, or a combination thereof.

Alternatively, starting material (v) may be polymeric. For example, starting material (v) may comprise a disilane such as bis(triethoxysilyl)hexane), 1,4-bis[trimethoxysilyl(ethyl)]benzene, and bis[3-(triethoxysilyl)propyl] tetrasulfide.

Starting material (v) can be one single crosslinker or a combination comprising two or more crosslinkers that differ in at least one of the following properties: hydrolyzable substituents and other organic groups bonded to silicon, and when a polymeric crosslinker is used, siloxane units, structure, molecular weight, and sequence. Starting material (vi) is an adhesion promoter. Suitable adhesion promoters for starting material (vi) may comprise a hydrocarbonoxysilane such as an alkoxysilane, a combination of an alkoxysilane and a hydroxy-functional polyorganosiloxane, an aminofunctional silane, a mercaptofunctional silane, or a combination thereof. Adhesion promoters are known in the art and may comprise silanes having the formula R²⁴ _(t)R²⁵ _(u)Si(OR²⁶)_(4−(t+u)) where each R²⁴ is independently a monovalent organic group having at least 3 carbon atoms; R²⁵ contains at least one SiC bonded substituent having an adhesion-promoting group, such as amino, epoxy, mercapto or acrylate groups; subscript t has a value ranging from 0 to 2; subscript u is either 1 or 2; and the sum of (t+u) is not greater than 3. Alternatively, the adhesion promoter may comprise a partial condensate of the above silane. Alternatively, the adhesion promoter may comprise a combination of an alkoxysilane and a hydroxy-functional polyorganosiloxane.

Alternatively, the adhesion promoter may comprise an unsaturated or epoxy-functional compound. The adhesion promoter may comprise an unsaturated or epoxy-functional alkoxysilane. For example, the functional alkoxysilane can have the formula (XX): R²⁷ _(v)Si(OR²⁸)_((4−v)), where subscript v is 1, 2, or 3, alternatively subscript v is 1. Each R²⁷ is independently a monovalent organic group with the proviso that at least one R²⁷ is an unsaturated organic group or an epoxy-functional organic group. Epoxy-functional organic groups for R²⁷ are exemplified by 3-glycidoxypropyl and (epoxycyclohexyl)ethyl. Unsaturated organic groups for R²⁷ are exemplified by 3-methacryloyloxypropyl, 3-acryloyloxypropyl, and unsaturated monovalent hydrocarbon groups such as vinyl, allyl, hexenyl, undecylenyl. Each R²⁸ is independently a saturated hydrocarbon group of 1 to 4 carbon atoms, alternatively 1 to 2 carbon atoms. R²⁸ is exemplified by methyl, ethyl, propyl, and butyl.

Examples of suitable epoxy-functional alkoxysilanes include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, (epoxycyclohexyl)ethyldimethoxysilane, (epoxycyclohexyl)ethyldiethoxysilane and combinations thereof. Examples of suitable unsaturated alkoxysilanes include vinyltrimethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, hexenyltrimethoxysilane, undecylenyltrimethoxysilane, 3-methacryloyloxypropyl trimethoxysilane, 3-methacryloyloxypropyl triethoxysilane, 3-acryloyloxypropyl trimethoxysilane, 3-acryloyloxypropyl triethoxysilane, and combinations thereof.

Alternatively, the adhesion promoter may comprise an epoxy-functional siloxane such as a reaction product of a hydroxy-terminated polyorganosiloxane with an epoxy-functional alkoxysilane, as described above, or a physical blend of the hydroxy-terminated polyorganosiloxane with the epoxy-functional alkoxysilane. The adhesion promoter may comprise a combination of an epoxy-functional alkoxysilane and an epoxy-functional siloxane. For example, the adhesion promoter is exemplified by a mixture of 3-glycidoxypropyltrimethoxysilane and a reaction product of hydroxy-terminated methylvinylsiloxane with 3-glycidoxypropyltrimethoxysilane, or a mixture of 3-glycidoxypropyltrimethoxysilane and a hydroxy-terminated methylvinylsiloxane, or a mixture of 3-glycidoxypropyltrimethoxysilane and a hydroxy-terminated methylvinyl/dimethylsiloxane copolymer.

Alternatively, the adhesion promoter may comprise an aminofunctional silane, such as an aminofunctional alkoxysilane exemplified by H₂N(CH₂)₂Si(OCH₃)₃, H₂N(CH₂)₂Si(OCH₂CH₃)₃, H₂N(CH₂)₃Si(OCH₃)₃, H₂N(CH₂)₃Si(OCH₂CH₃)₃, CH₃NH(CH₂)₃Si(OCH₃)₃, CH₃NH(CH₂)₃Si(OCH₂CH₃)₃, CH₃NH(CH₂)₅Si(OCH₃)₃, CH₃NH(CH₂)₅Si(OCH₂CH₃)₃, H₂N(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, H₂N(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃, CH₃NH(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, CH₃NH(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃, C₄H₉NH(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, C₄H₉NH(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃, H₂N(CH₂)₂SiCH₃(OCH₃)₂, H₂N(CH₂)₂SiCH₃(OCH₂CH₃)₂, H₂N(CH₂)₃SiCH₃(OCH₃)₂, H₂N(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₃SiCH₃(OCH₃)₂, CH₃NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₅SiCH₃(OCH₃)₂, CH₃NH(CH₂)₅SiCH₃(OCH₂CH₃)₂, H₂N(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂, H₂N(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂, CH₃NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, C₄H₉NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂, C₄H₉NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, N-(3-(trimethoxysilyl)propyl)ethylenediamine, and a combination thereof.

Alternatively, the adhesion promoter may comprise a mercaptofunctional alkoxysilane, such as 3-mercaptopropyltrimethoxysilane or 3-mercaptopropyltriethoxysilane.

The exact amount of starting material (vi) depends on various factors including the type of adhesion promoter selected and the end use of the composition and its reaction product. However, starting material (vi), when present, may be added to the composition in an amount ranging from 0.01 to 50 weight parts based on the weight of the composition, alternatively 0.01 to 10 weight parts, and alternatively 0.01 to 5 weight parts. Starting material (vi) may be one adhesion promoter. Alternatively, starting material (vi) may comprise two or more different adhesion promoters that differ in at least one of the following properties: structure, viscosity, average molecular weight, polymer units, and sequence.

When selecting ingredients for the condensation reaction curable composition described above, there may be overlap between types of starting materials because certain starting materials described herein may have more than one function. For example, certain alkoxysilanes may be useful as filler treating agents, as adhesion promoters, and as crosslinkers.

Alternatively, the crosslinker, the filler, and the adhesion promoter may each be present in the composition. In this embodiment, the crosslinker may comprise an alkyl trialkoxysilane, such as methyltrimethoxysilane; the filler may comprise an extending filler such as calcium carbonate; and the adhesion promoter may comprise an alkoxysilane other than the crosslinker, such as N-(3-(trimethoxysilyl)propyl)ethylenediamine, 3-mercaptopropyltrimethoxysilane, or both

The composition described above may be prepared as a one part composition, for example, by combining all ingredients by any convenient means, such as mixing. For example, a one-part composition may be made by optionally combining (e.g., premixing) (i) the alkoxy-functional polyorganosiloxane with all or part of (iii) the filler, when present; and mixing this with a pre-mix comprising the catalyst (ii) and, when present (v) the crosslinker. Other additives such as an anti-aging additive and a pigment may be added to the mixture at any desired stage. A final mixing step may be performed under substantially anhydrous conditions, and the resulting compositions are generally stored under substantially anhydrous conditions, for example in sealed containers, until ready for use.

Alternatively, the composition may be prepared as a multiple part (e.g., 2 part) composition when a crosslinker is present. In this instance the catalyst and crosslinker are stored in separate parts, and the parts are combined shortly before use of the composition. For example, a two part curable composition may be prepared by combining ingredients comprising the alkoxy-functional polyorganosiloxane and the crosslinker to form a first (curing agent) part by any convenient means such as mixing. A second (base) part may be prepared by combining starting materials comprising a catalyst and the alkoxy-functional polyorganosiloxane by any convenient means such as mixing. The starting materials may be combined at ambient or elevated temperature and under ambient or anhydrous conditions, depending on various factors including whether a one part or multiple part composition is selected. The base part and curing agent part may be combined by any convenient means, such as mixing, shortly before use. The base part and curing agent part may be combined in relative amounts of base: curing agent ranging from 1:1 to 10:1.

The equipment used for mixing the starting materials is not specifically restricted. Examples of suitable mixing equipment may be selected depending on the type and amount of each ingredient selected. For example, agitated batch kettles may be used for relatively low viscosity compositions, such as compositions that would react to form gums or gels. Alternatively, continuous compounding equipment, e.g., extruders such as twin screw extruders, may be used for more viscous compositions and compositions containing relatively high amounts of particulates. Exemplary methods that can be used to prepare the compositions described herein include those disclosed in, for example, U.S. Patent Publications US 2009/0291238 and US 2008/0300358.

These compositions made as described above may be stable when the stored in containers that protect the compositions from exposure to moisture, but these compositions may react via condensation reaction when exposed to atmospheric moisture.

EXAMPLES

These examples are intended to illustrate some embodiments of the invention and should not be interpreted as limiting the scope of the invention set forth in the claims. In the examples below, the examples were performed under conditions including an oxidant, e.g., 2% oxygen. The following starting materials and abbreviations are defined as follows:

Abbreviation Definition TMDS 1,1,3,3-tetramethyldisiloxane, example of starting material A) M′D′M′ 1,1,3,5,5-pentamethyltrisiloxane, example of starting material A) M′T^(Pr) Siloxane oligomer having 3 (Me₂HSiO_(1/2)) units and having one (PrSiO_(3/2)) unit, where Me represents a methyl group and Pr represents a propyl group. VTMS Vinyltrimethoxysilane, example of starting material B) [Ir(COD)Cl]2 [Ir(1,5-cyclooctadiene)Cl]₂ example of starting material C) THF Tetrahydrofuran, example of a solvent GC-FID Gas chromatography with flame ionization detection GC-MS Gas chromatography, mass spectrometry MeSi(OMe)₃ Methyl trimethoxysilane Ti(OiPr)₂(EAA)₂ Titanium Diisopropoxide Di(Ethyl Acetoacetate) Ti(OBu)₄ Titanium tetrabutoxide (MeO)₃Si(CH₂)SH Thiopropyl Trimethoxysilane (MeO)₃Si(CH₂)₃NH(CH₂)₂NH₂ Aminoethylaminopropyl Trimethoxysilane Me Methyl Et Ethyl Vi Vinyl

“Yield” means molar amount alkoxy-functional organohydrogensiloxane oligomer produced/molar amount alkoxy-functional organohydrogensiloxane oligomer possible based on the amount of limiting reagent (the aliphatically unsaturated alkoxysilane). “Selectivity” means the ratio of linear isomer/branched isomer of the alkoxy-functional organohydrogensiloxane (where isomers have the same molecular weight).

Example 1

In an air-free glovebox, a mixture of 13.8 g of VTMS and 15.2 g of TMDS was loaded into a 100 mL round bottom flask. The mixture was then pre-heated to 70° C., vigorously stirred with a stirbar, and then 226 μL of a 0.005 M solution of [Ir(1,5-cyclooctadiene)Cl]₂ in toluene was added. An exotherm and bubbling were initially observed. The reaction mixture was allowed to react for 16 h. The reaction mixture was then purified by distillation, which resulted in a light fraction (solvents, unreacted reagents, and light byproducts), a desired product fraction, and a heavy fraction which was left behind in the distillation flask. The yield of the desired product fractions was 14.73 g (50.8%), and consisted of approximately 93% of the linear isomer, 2% of the branched isomer, and 5% of the dehydrogenative silylation product. Significant amounts of unreacted starting materials were observed, and interestingly only trace amounts of the double hydrosilylation product were observed.

Example 2 (Comparative

In an air-free glovebox, a mixture of 1.1 g of VTMS, 1 g of TMDS, and 0.25 g of dodecane (internal standard) was added to a 20 mL scintillation vial containing a stirbar. Then 30 μL of a 0.01 M solution of Rh(PPh₃)₃Cl in THF was added (this reagent solution was heated to 60° C. with stirring in order to dissolve the poorly soluble catalyst). After stirring at room temperature for 30 min, the reaction mixture was heated to 50° C. for 16 h. At this stage, an aliquot (˜150 μL) of the reaction mixture was withdrawn and injected into a GC vial, and diluted with ˜1 mL of xylene. The reaction was analyzed by GC-FID and GC-MS. Analysis indicated ˜54% yield of the linear product with 8% of the branched isomer detected. A small amount of unreacted starting materials were observed. This Example 2 shows less selectivity than example 1 to the desired beta-adduct in the product.

Example 3 (Comparative)—Preparation of Ethyltrimethoxysilyl-Terminated Tetramethyldisiloxane

In an air-free glovebox, a mixture of 1.1 g of VTMS, 1 g of TMDS, and 0.25 g of dodecane (internal standard) was added to a 20 mL scintillation vial containing a stirbar. Then 30 μL of a 0.01 M solution of Pt in THF in the form of Karstedt's catalyst (supplied as 2% in xylene, Sigma Aldrich) was added (this reagent solution was heated to 60° C. with stirring in order to dissolve the poorly soluble catalyst). After stirring at room temperature for 30 min, the reaction mixture was heated to 50° C. for 16 h. At this stage, an aliquot (˜150 μL) of the reaction mixture was withdrawn and injected into a GC vial, and diluted with ˜1 mL of xylene. The reaction was analyzed by GC-FID and GC-MS. Analysis indicated ˜46% yield of the linear product with 26% of the branched isomer detected. A small amount of unreacted tetramethyldisiloxane was observed but all of the vinyltrimethoxysilane was observed.

Example 4 (Comparative)—Preparation of di(trimethoxysilylethyl)pentamethyltrisiloxane (M′D′M′ EHM

A solution of 1% Pt catalyst in toluene was prepared. VTM in an amount of 18.05 g was added at a rate of 275 μL/min to a flask containing 11.97 g M′D′M′ in at a temperature of 40° C. under N₂ with rapid stirring while cooling the flask, by means of a syringe pump. 5% of the total VTM was initially added, followed by 10 pm Pt catalyst (39 μL of the 1% solution Pt in toluene) to start the exotherm, and then the addition of the remaining VTM was begun. The temperature was monitored by a thermocouple and kept below 80° C. by controlling the addition rate. After the complete addition of VTM, the reaction solution was stirred at 75° C. for 0.5 h, allowed to cool, and characterized by GC which showed the product mixture contained 10% monofunctional oligomer, 68% difunctional oligomer, and 20% trifunctional oligomer. The sample was purified by distillation under 1 Torr (0.1333 kPa) to give 16.9 g M′D′M′ EHM (yield: 56%) with a boiling point of 135-137° C. at 1 Torr (0.1333 kPa). The sample was characterized by GC, ¹H, and ²⁹Si NMR. The final product was composed of 66% β isomers of M′D′H′ EHM and 34% a isomers of M′D′M′ EHM; 60% D-H isomer (first product structure in the reaction scheme shown below) and 40% M-H isomer (second product structure in the reaction scheme shown below). ¹H NMR (CDCl₃): δ 4.69 (M-H), 4.62 (D-H), 3.55 (—OCH₃), 1.06 (—CH₃ from α isomer), 0.56 (—CH₂CH₂— from β isomer), 0.25 to 0 (—CH₃ and —CH(Me)—). ²⁹Si NMR (CDCl₃): δ11 to 9 (M-D′), 9 to 7 (M-D), −6 to −8 (M′), −19 to −23 (D), −35 to −38 (D′), −40 to −43 (7).

Example 5 (Prophetic)—Preparation of di(trimethoxysilylethyl)pentamethyltrisiloxane (M′D′M′ EHM

A 0.005 M solution of [Ir(1,5-cyclooctadiene)Cl]₂ in toluene will be prepared. A three-neck round bottom flask fitted with a thermocouple and a cold water condenser will be charged with 9.96 g of this catalyst and 15.04 g VTM. The flask will be purged with N₂, and the mixture in the flask will be heated to 80° C., followed by the addition of catalyst solution (1 mL). After 17 h stirring at 80° C. under N₂, the reaction mixture will be allowed to cool to room temperature of 25° C. and will be analyzed by GC.

Example 6 (Comparative)—Preparation of di(trimethoxysilylethyl) Siloxane Oligomer (Pr-T EHM

The procedure of Example 4 was repeated, except that M′T^(Pr) (15.0 g), VTM (15.0 g), and platinum catalyst solution in toluene 39 μL) were used as starting materials. The crude product contained 14% monofunctional oligomer, 54% difunctional oligomer, and 31% trifunctional oligomer by GC (FID). The sample was purified by distillation under 1 Torr (0.1333 kPa) to give 13.5 g pure Pr-T EHM (yield: 45%). This was characterized by GC (retention time: 30.8-31.1 min), ¹H, and ²⁹Si NMR. This sample was composed of 70% β isomer of Pr-T EHM and 30% a isomer of Pr-T EHM. ¹H NMR (CDCl₃): δ 4.69 (Si—H), 3.55 (—OCH₃), 1.36 (CH₃CH₂CH₂—), 1.09 (—CH₃ from α isomer), 0.92 (CH₃CH₂CH₂—), 0.56 (—CH₂CH₂— from βisomer), 0.45 (CH₃CH₂CH₂—), 0.2 to 0 (—SiCH₃). ²⁹Si NMR (CDCl₃): δ10 to 7 (M), −6 to −8 (M′), −40 to −43 (T-OMe), −63 to −65 (T-Pr).

Example 7—Preparation of di(trimethoxysilylethyl-pentamethyltrisiloxane (Pr-T EHM) (Prophetic

The procedure of Example 5 will be repeated, except that M′T^(Pr) (29.7 g), VTM (29.7 g), and a 0.005 M solution of [Ir(1,5-cyclooctadiene)Cl]₂ in toluene was added will be used as starting materials. The reaction will be conducted at 80° C. for 7 h.

Example Product β/α ratio 4 (comparative) M′D′M′ EHM 66/34 6 (comparative) Pr-T EHM 70/30

Example 8—Preparation of Ethyl(dimethoxymethyl)silyl-terminated Tetramethyldisiloxane

To a 250 mL round bottom flask containing 13.84 g HSiMe₂OSiMe₂H and a stirbar, was affixed an addition funnel containing 9.080 g of ViSiMe(OMe)₂ (where Me represents methyl, and Vi represents vinyl). 0.1 mL of [Ir(COD)Cl]₂ solution in toluene (0.05 M in Ir) was added to the vinyl reagent. The ViSiMe(OMe)₂ was dripped into the flask at 1 drop/sec, and there was a gradual exotherm up to ˜55 C. At this point, ˜0.1 mL of [Ir(COD)Cl]₂ solution was added to the flask, and the temperature began to rise at a somewhat faster rate. The drip of the ViSiMe(OMe)₂ was continued at 1 drop/sec until complete, and the temperature maxed out at 70° C. After cooling to 50° C., an additional 0.1 mL of [Ir(COD)Cl]₂ solution was added; no additional exotherm was observed, and so the reaction was judged as complete. A gas chromatography-mass spectrometry/flame ionization detection (GC-MS/FID) of the reaction mixture indicated high conversion to the product HSiMe₂OSiMe₂CH₂CH₂SiMe(OMe)₂ (˜91.2%). This example demonstrated that the catalyst is active towards substrates in which there is variation in the formula ViSiMe_(x)(OMe)_((3−x)), where subscript x can be 0 to 3.

Example 9—Preparation of Ethyl(triethoxy)silyl-terminated Tetramethyldisiloxane

A 250 mL flask was loaded with 71.57 g of tetramethyldisiloxane, and to the flask was affixed a reflux condenser, addition funnel, and septa through which was inserted thermocouples for temperature logging and control. The addition funnel was loaded with 78 g of vinyltriethoxysilane (VTM) as well as 0.4 mL of 0.05 M Ir ([Ir(COD)Cl]₂ in toluene). The contents of the flask were heated to 50° C. and then a drip of the VTM/Ir mixture was fed into the flask at 1 drop/sec. An exotherm initiated and was allowed to gradually proceed up to 80° C. by the end of the addition. After the addition was completed, the reaction mixture was externally heated at 70° C. for an additional 2 h. At this point, the reaction mixture was analyzed by GC-FID. The mass balance based on species derived from ViSi(OEt)₃ was 0.6% ViSi(OEt)₃, 3.2% EtSi(OEt)₃, and 95.3% HSiMe₂OSiMe₂CH₂CH₂Si(OEt)₃, 1.6% HSiMe₂OSiMe₂CMeHSi(OEt)₃, and 0.6% HSiMe₂OSiMe₂CHCHSi(OEt)₃. This example demonstrates that variation in the identity of the alkoxy groups in (B) the aliphatically unsaturated alkoxysilane can be tolerated by the catalyst.

Example 10—Preparation of Propyl(trimethoxy)silyl-terminated Tetramethyldisiloxane

A 250 mL flask was loaded with 25 g of TMDS, and affixed with a condenser, thermocouples for temperature control and logging, and an addition funnel pre-loaded with AllylSi(OMe)₃. After preheating to 50° C., the addition of AllylSi(OMe)₃ was started at 2 drop/sec. An initial small exotherm was observed, heating to 55° C., but after that the temperature began to fall. At this point (25% of AllylSi(OMe)₃ added) 0.4 mL of additional Ir solution was added, and no additional exotherm was observed. The flask was then heated to 70° C. for 1 h. At this point, a GC aliquot indicated a yield of 7.5% of HSiMe₂OSiMe₂(CH₂)₃Si(OMe)₃. Other detected byproducts were 0.7% HSiMe₂OSiMe₂(C₃H₄)Si(OMe)₃, 6.5% Me₃Si(CH₂)₃Si(OMe)₃, 58.8% unreacted CH-₂CH₂CH₂Si(OMe)₃, 16.9% isomerized CH₃CHCHSi(OMe)₃, 9.3% CH₃CH₃CH₃Si(OMe)₃. Other trace byproducts were detected but further identification was difficult. This example demonstrates that the catalyst is tolerant of substrates in which methylene spacers are placed between the terminal aliphatic unsaturation in (B) the alkoxysilane, e.g., Vi(CH₂)_(x)Si(OMe)₃, under the conditions tested in this example.

Example 11—Preparation of Ethyl(trimethoxy)silyl-terminated Pentamethyldisiloxane

To a flask containing 19.07 g HSiMe₂OSiMe₃ and a stirbar, was affixed an addition funnel containing 12.7 g ViSi(OMe)₃, a condenser, and a septa through which was inserted thermocouples for temperature control. 0.1 mL of [Ir(COD)Cl]₂ solution in toluene (0.05 M in Ir) was added to the vinyl reagent. After preheating the flask to 50° C., the ViSi(OMe)₃/Ir mixture was added dropwise at 1 drop/sec. A 2° C. exotherm was initially noted, but rapidly diminished and no further exotherm was observed. After the addition of vinyl reagent and Ir was complete, the reaction mixture was allowed to react for 15 min and an aliquot for GC-MS was recorded. Very little reaction had occurred, with 0.7% Me₃SiOSiMe₂(CH₂)₂Si(OMe)₃ and 6.1% HSiMe₂OSiMe₂(CH₂)₂Si(OMe)₃. The latter apparently arises from the redistribution of the starting material; Me₃SiOSiMe₃ is also observed. This example demonstrated that catalytic hydrosilylation of hydrosilane substrates containing less than two Si—H groups can be performed under the conditions tested in this example.

Example 12—Preparation of Ethyl(trimethoxy)silyl-terminated Polydimethylsiloxane

To a vial containing of 5.00 g of a polymer primarily composed of HSiMe₂O(SiMe₂O)₂₀SiMe₂H was added 1.01 g of ViSi(OMe)₃. The mixture was stirred until blended, and then 153 μL of [Ir(COD)Cl]₂ was added (0.05M in Ir). A small exotherm was felt in the vial, though it is difficult to tell by hand. After stirring at room temperature for 72 h, the reaction mixture was dissolved in d8-toluene and analyzed by 1H NMR. Mass balance of the ViSi(OMe)₃ reagent indicated that 46.5% remained unreacted, 20.9% had undergone linear hydrosilylation onto the polymer, and 32.6% had been hydrogenated into EtSi(OMe)₃. All of the initial Si—H had been consumed. This example demonstrates that the Ir catalyst is able to catalyze hydrosilylation on polymeric substrates, although there are some byproducts.

Composition Example (Reference 1)—Compounding Procedure for Sealant Composition Samples

To a speed mixer cup was added 210.88 g of a trimethoxy-functional polydimethylsiloxane prepared by hydrosilylation reaction of an ethyltrimethoxysilyl-terminated tetramethyldisiloxane (prepared in an example as described above) and an α,ω-vinyl-terminated polydimethylsiloxane. A slurry of methyltrimethoxysilane, tetra-n-butoxy titanate, 3-mercaptopropyltrimethoxysilane, slurry of 80% titanium ethyl acetoacetate 20% methyltrimethoxysilane, and N-(3-(trimethoxysilyl)propyl)ethylenediamine was prepared in a ratio equivalent to the ratio shown in a table below. From this slurry, 13.16 g was added to the speed mixer cup. The cup was mixed in a DAC 600.2 VAC-P Speedmixer for 30 seconds at 800 revolutions per minute (rpm), then 30 seconds at 1500 rpm. Next, 149.2 g of precipitated calcium carbonate was added to the cup and mixed 30 seconds at 800 rpm, and 30 seconds at 1500 rpm. The sides and bottom of the cup were then scraped by hand with a spatula. Next 26.76 g of ground calcium carbonate was added to the cup and it was mixed for 30 seconds at 800 rpm and 30 seconds at 1500 rpm. Again, the sides and bottom of the cup were hand scraped with a spatula. Finally, the cup was fitted with a cap that contained a hole as to allow the contents of the cup to be exposed to a vacuum environment. The cup was de-aired by mixing 30 seconds at 800 rpm and 5 psi (34.5 kPa), 30 seconds at 1500 rpm and 5 psi (34.5 kPa), and 30 seconds at 800 rpm and 14.7 psi (101.35 kPa) The resulting sealant composition was transferred to Semco® tubes via a hand operated cup press.

In these comparative examples 13 and 14, two comparative samples were prepared using the procedure above and including the starting materials in the table below.

Amount Speedmixer Starting Materials (g) Comparative sample using Polydimethylsiloxane 100% end capped with 70% β 210.88 polydimethylsiloxane 100% ethyltrimethoxysilyl group containing endcapped with the tetramethyldisiloxane and 30% α ethyltrimethoxy ethyltrimethoxysilyl-terminated silyl group containing tetramethyldisiloxane (the tetramethyldisiloxane prepared in ethyltrimethoxysilyl-terminated tetramethyldisiloxane Comparative Example 3) prepared in comparative Example 3) Precipitated Calcium Carbonate 149.2 Ground Calcium Carbonate 26.76 Methyltrimethoxysilane 7.36 Tetra-n-butoxy titanate 1.32 3-Mercaptopropyltrimethoxysilane 0.76 Slurry 80% Titanium Ethyl Acetoacetate 20% 3.52 Methyltrimethoxysilane N-(3-(Trimethoxysilyl)propyl)ethylenediamine 0.2

In these examples 15 and 16, two sealant composition samples will be prepared according to the table below.

Amount Speedmixer Component (g) (Prophetic) Samples will be prepared Polydimethylsiloxane 100% end capped 210.88 using a polydimethylsiloxane capped with the ethyltrimethoxy-functional with a product prepared as described siloxanes prepared in Example 1, 2, 6, or 8 in Example 1, 2, 6, and 8 Precipitated Calcium Carbonate 149.2 Ground Calcium Carbonate 26.76 Methyltrimethoxysilane 7.36 Tetra-n-butoxy titanate 1.32 3-Mercaptopropyltrimethoxysilane 0.76 Slurry 80% Titanium Ethyl Acetoacetate 3.52 20% Methyltrimethoxysilane N-(3-(Trimethoxysilyl)propyl)ethylenediamine 0.2

The composition samples prepared as described above will be evaluated using the following test methods for Tack Free Time (TFT) and Skin Over Time (SOT).

TFT was tested as follows. A 100 mil slab of sealant was drawn down on a piece of polyethylene terephthalate (PET). A small strip of PET is then lightly pressed onto the surface of the sealant to check for cure. When no sealant is transferred to the strip of PET, the sealant is considered tack free.

SOT was tested as follows. A 100 mil slab of sealant was drawn down on a piece of PET. A sealant is considered to have become skinned over when no sealant transfers to a gloved or bare finger when lightly touched.

The table below shows testing done on the comparative sealant composition samples prepared as described above. On an 8 millimeter (mm) parallel plate constant stress rheometer, a dollop of uncured sealant was pressed to 1.829 mm and trimmed with a razor blade. The sealant was cured in place for the time specified. Next, a constant stress of 0.5 psi (3.45 kPa) was applied for the time specified. The stress was then released and the sealant was allowed to recover for five minutes. Sealant with a faster cure will creep less during the stress period, and will recover more closely to zero during the recovery period.

TFT SOT Sample # Description (min) (min) Sealant Comparative sample using polydimethylsiloxane 40 19 Composition 1 100% endcapped with the ethyltrimethoxysilyl- (comparative) terminated tetramethyldisiloxane prepared in Comparative Example 3) 70% β 30% α Sealant Comparative sample using polydimethylsiloxane 36 22 Composition 2 100% endcapped with the ethyltrimethoxysilyl- (comparative) terminated tetramethyldisiloxane prepared in Comparative Example 3)

Composition Example (Reference 2)—Compounding Procedure for Sealant Composition Samples (Reference 2)

To a speed mixer cup was added the polymer referenced in a table below. A slurry of methyltrimethoxysilane, slurry of 80% titanium ethyl acetoacetate 20% methyltrimethoxysilane, tetra-n-butoxy titanate, 3-mercaptopropyltrimethoxysilane, and N-(3-(trimethoxysilyl)propyl)ethylenediamine was prepared in a ratio equivalent to the ratio seen in the above formulations. Note that not all starting materials were in every slurry, see tables below. To the cup was added this slurry equivalent to the sum of its starting materials. The cup was then mixed in a DAC 600.2 VAC-P Speedmixer for one minute at 1500 rpm. Next, the allotment of precipitated calcium carbonate and ground calcium carbonate, where used, was added to the cup and mixed 30 seconds at 2000 rpm. Finally, the cup was fitted with a cap that contained a hole as to allow the contents of the cup to be exposed to a vacuum environment. The cup was de-aired by mixing 30 seconds at 800 rpm and 5 psi (34.5 kPa), 30 seconds at 1500 rpm and 5 psi (34.5 kPa), and 30 seconds at 800 rpm and 14.7 psi (101.35 kPa). The resulting sealant was transferred to Semco® tubes via a hand operated cup press. A reasonable variance was allowed when adding ingredients.

Test Method Reference Example 3—Creep and Recovery Procedure

On an AR 550 constant stress parallel plate rheometer, a disc of sealant prepared according to Reference Example 3, 8 mm in diameter, and 1.829 mm in thickness was cured for forty-five minutes. Next, a constant stress of 0.5 psi (3.45 kPa) was applied to the sealant for twenty seconds, and the strain was recorded as creep. The stress was released, and the recovery was measured for two minutes. Sealants that cure faster will have lower creep values, and will have recovery values closer to zero.

Test Method Reference Example 4—Tack-Free Time Procedure

A 100-mil thick slab of sealant prepared according to Reference Example 3 was drawn down on PET and cured in standard laboratory conditions (RT and ambient pressure). A small piece of PET was lightly pressed onto the surface of the sealant and peeled off. Tack-free time was recorded when the small piece of PET was peeled from the sealant with no residue.

Test Method Reference Example 5—Skin-Over Time Procedure

A 100-mil thick slab of sealant prepared according to Reference Example 3 was drawn down on PET and cured in standard laboratory conditions. Skin-over time was recorded when no sealant transferred to a finger tip when lightly touched.

Amount Speedmixer Component (g) Sample 17 Polydimethylsiloxane 100% end capped 207.19 with 66.4% β ethyltrimethoxysilyl group containing tetramethyldisiloxane and 33.6% α ethyltrimethoxy silyl group containing tetramethyldisiloxane (the ethyltrimethoxysilyl-terminated tetramethyldisiloxane prepared as in Comparative Example 3) Precipitated Calcium Carbonate 150.04 Methyltrimethoxysilane 8.88 Slurry 80% Titanium Ethyl Acetoacetate 3.70 20% Methyltrimethoxysilane N-(3- 0.19 (Trimethoxysilyl)propyl)ethylenediamine

Amount Speedmixer Component (g) Sample 18 Polydimethylsiloxane 100% end capped 207.19 with 76.6% β ethyltrimethoxysilyl group containing tetramethyldisiloxane and 23.4% α ethyltrimethoxy silyl group containing tetramethyldisiloxane (the ethyltrimethoxysilyl-terminated tetramethyldisiloxane used in this sample was a blend prepared from the ethyltrimethoxysilyl group containing tetramethyldisiloxanes in Comparative Example 3 and Example 1 to achieve the 76.6/23.4 isomer ratio) Precipitated Calcium Carbonate 150.04 Methyltrimethoxysilane 8.88 Slurry 80% Titanium Ethyl Acetoacetate 3.70 20% Methyltrimethoxysilane N-(3- 0.19 (Trimethoxysilyl)propyl)ethylenediamine

Amount Speedmixer Component (g) Sample 19 Polydimethylsiloxane 100% end capped 207.19 with 86.8% β ethyltrimethoxysilyl group containing tetramethyldisiloxane and 13.2% α ethyltrimethoxy silyl group containing tetramethyldisiloxane (the ethyltrimethoxysilyl-terminated tetramethyldisiloxane was a blend prepared from the ethyltrimethoxysilyl group containing tetramethyldisiloxanes in Comparative Example 3 and Example 1 to achieve 86.8/13.2 isomer ratio) Precipitated Calcium Carbonate 150.04 Methyltrimethoxysilane 8.88 Slurry 80% Titanium Ethyl Acetoacetate 3.70 20% Methyltrimethoxysilane N-(3- 0.19 (Trimethoxysilyl)propyl)ethylenediamine

Amount Speedmixer Component (g) Sample 20 Polydimethylsiloxane 100% end capped 207.19 with 96.4% β ethyltrimethoxysilyl group containing tetramethyldisiloxane and 3.6% α ethyltrimethoxy silyl group containing tetramethyldisiloxane (the ethyltrimethoxysilyl-terminated tetramethyldisiloxane prepared as in Example 1) Precipitated Calcium Carbonate 150.04 Methyltrimethoxysilane 8.88 Slurry 80% Titanium Ethyl Acetoacetate 3.70 20% Methyltrimethoxysilane N-(3- 0.19 (Trimethoxysilyl)propyl)ethylenediamine

Amount Speedmixer Component (g) Sample 21 Polydimethylsiloxane 100% end capped 207.19 with 65% β 35% α di-ethyltrimethoxysilyl groups (prepared as in Comparative Example 6) Precipitated Calcium Carbonate 150.04 Methyltrimethoxysilane 8.88 Slurry 80% Titanium Ethyl Acetoacetate 3.70 20% Methyltrimethoxysilane N-(3- 0.19 (Trimethoxysilyl)propyl)ethylenediamine

Amount Speedmixer Component (g) Sample 22 Polydimethylsiloxane 100% end capped 207.19 (prophetic) with 95% β 5% α di-ethyltrimethoxysilyl groups Precipitated Calcium Carbonate 150.04 Methyltrimethoxysilane 8.88 Slurry 80% Titanium Ethyl Acetoacetate 3.70 20% Methyltrimethoxysilane N-(3- 0.19 (Trimethoxysilyl)propyl)ethylenediamine

Creep Recovery SOT TFT Sample Description (%) (%) (min) (min) Sample 17 66.4% β ETM 124.6 14 20 46 (comparative) Sample 18 76.6% β ETM 78.8 6.2 18 36 (comparative) Sample 19 86.8% β ETM 43.6 2.8 13 32 (comparative) Sample 20 96.4% β ETM 22.7 1.5 13 25 (practical) Sample 21   65% β EHM 26.0 1.4 10 23 (comparative) Sample 22   95% β EHM 22.9 1.2 7 17 (practical)

Amount Speedmixer Component (g) Sample 23 Polydimethylsiloxane 100% end capped 163.47 with 66.4% β ethyltrimethoxysilyl group containing tetramethyldisiloxane and 33.6% α ethyltrimethoxy silyl group containing tetramethyldisiloxane (the ethyltrimethoxysilyl-terminated tetramethyldisiloxane prepared as in Comparative Example 3) Precipitated Calcium Carbonate 118.53 Ground Calcium Carbonate 9.75 Methyltrimethoxysilane 4.83 Slurry 80% Titanium Ethyl Acetoacetate 2.25 20% Methyltrimethoxysilane Tetra-n-butoxy titanate 0.84 3-Mercaptopropyltrimethoxysilane 0.33

Amount Speedmixer Component (g) Sample 24 Polydimethylsiloxane 100% end capped 163.47 with 76.6% β ethyltrimethoxysilyl group containing tetramethyldisiloxane and 23.4% α ethyltrimethoxy silyl group containing tetramethyldisiloxane (the ethyltrimethoxysilyl-terminated tetramethyldisiloxane used in this sample was a blend prepared from the ethyltrimethoxysilyl group containing tetramethyldisiloxanes in Comparative Example 3 and Example 1 to achieve the 76.6/23.4 isomer ratio) Precipitated Calcium Carbonate 118.53 Ground Calcium Carbonate 9.75 Methyltrimethoxysilane 4.83 Slurry 80% Titanium Ethyl Acetoacetate 2.25 20% Methyltrimethoxysilane Tetra-n-butoxy titanate 0.84 3-Mercaptopropyltrimethoxysilane 0.33

Amount Speedmixer Component (g) Sample 25 Polydimethylsiloxane 100% end capped 163.47 with 86.8% β ethyltrimethoxysilyl group containing tetramethyldisiloxane and 13.2% α ethyltrimethoxy silyl group containing tetramethyldisiloxane (the ethyltrimethoxysilyl-terminated tetramethyldisiloxane was a blend prepared from the ethyltrimethoxysilyl group containing tetramethyldisiloxanes in Comparative Example 3 and Example 1 to achieve 86.8/13.2 isomer ratio) Precipitated Calcium Carbonate 118.53 Ground Calcium Carbonate 9.75 Methyltrimethoxysilane 4.83 Slurry 80% Titanium Ethyl Acetoacetate 2.25 20% Methyltrimethoxysilane Tetra-n-butoxy titanate 0.84 3-Mercaptopropyltrimethoxysilane 0.33

Amount Speedmixer Component (g) Sample 26 Polydimethylsiloxane 100% end capped 163.47 with 96.4% β ethyltrimethoxysilyl group containing tetramethyldisiloxane and 3.6% α ethyltrimethoxy silyl group containing tetramethyldisiloxane (the ethyltrimethoxysilyl-terminated tetramethyldisiloxane prepared as in Example 1) Precipitated Calcium Carbonate 118.53 Ground Calcium Carbonate 9.75 Methyltrimethoxysilane 4.83 Slurry 80% Titanium Ethyl Acetoacetate 2.25 20% Methyltrimethoxysilane Tetra-n-butoxy titanate 0.84 3-Mercaptopropyltrimethoxysilane 0.33

Amount Speedmixer Component (g) Sample 27 Polydimethylsiloxane 100% end capped with 65% β 163.47 35% α di-ethyltrimethoxysilyl groups (prepared as in Comparative Example 6) Precipitated Calcium Carbonate 118.53 Ground Calcium Carbonate 9.75 Methyltrimethoxysilane 4.83 Slurry 80% Titanium Ethyl Acetoacetate 20% 2.25 Methyltrimethoxysilane Tetra-n-butoxy titanate 0.84 3-Mercaptopropyltrimethoxysilane 0.33

Amount Speedmixer Component (g) Sample 28 Polydimethylsiloxane 100% end capped with 163.47 (prophetic) 95% β 5% α di-ethyltrimethoxysilyl groups Precipitated Calcium Carbonate 118.53 Ground Calcium Carbonate 9.75 Methyltrimethoxysilane 4.83 Slurry 80% Titanium Ethyl Acetoacetate 2.25 20% Methyltrimethoxysilane Tetra-n-butoxy titanate 0.84 3-Mercaptopropyltrimethoxysilane 0.33

Creep Recovery SOT TFT Sample Description (%) (%) (min) (min) Sample 23 66.4% β ETM 188.0 39.9 11 30 (comparative) Sample 24 76.6% β ETM 107.4 10.6 5 25 (comparative) Sample 25 86.8% β ETM 61.9 4.4 13 28 (comparative) Sample 26 96.4% β ETM 43.3 3.1 7 22 (practical) Sample 27   65% β EHM 22.4 1.2 1 12 (comparative) Sample 28   95% β EHM 10.9 0.5 0 5 (practical)

Amount Speedmixer Component (g) Sample 29 Polydimethylsiloxane 100% end capped with 171.9 66.4% β ethyltrimethoxysilyl group containing tetramethyldisiloxane and 33.6% α ethyltrimethoxy silyl group containing tetra- methyldisiloxane (the ethyltrimethoxysilyl- terminated tetramethyldisiloxane prepared as in Comparative Example 3) Precipitated Calcium Carbonate 108.99 Ground Calcium Carbonate 62.1 Methyltrimethoxysilane 7.62 Slurry 80% Titanium Ethyl Acetoacetate 2.76 20% Methyltrimethoxysilane Tetra-n-butoxy titanate 1.26 3-Mercaptopropyltrimethoxysilane 0.87 N-(3-(Trimethoxysilyl)propyl)ethylenediamine 0.39

Amount Speedmixer Component (g) Sample 30 Polydimethylsiloxane 100% end capped with 171.9 76.6% β ethyltrimethoxysilyl group containing tetramethyldisiloxane and 23.4% α ethyltrimethoxy silyl group containing tetramethyldisiloxane (the ethyltrimethoxysilyl- terminated tetramethyldisiloxane used in this sample was a blend prepared from the ethyltrimethoxysilyl group containing tetramethyldisiloxanes in Comparative Example 3 and Example 1 to achieve the 76.6/23.4 isomer ratio) Precipitated Calcium Carbonate 108.99 Ground Calcium Carbonate 62.1 Methyltrimethoxysilane 7.62 Slurry 80% Titanium Ethyl Acetoacetate 20% 2.76 Methyltrimethoxysilane Tetra-n-butoxy titanate 1.26 3-Mercaptopropyltrimethoxysilane 0.87 N-(3-(Trimethoxysilyl)propyl)ethylenediamine 0.39

Amount Speedmixer Component (g) Sample 31 Polydimethylsiloxane 100% end capped with 171.9 86.8% β ethyltrimethoxysilyl group containing tetramethyldisiloxane and 13.2% α ethyltrimethoxy silyl group containing tetra- methyldisiloxane (the ethyltrimethoxysilyl- terminated tetramethyldisiloxane was a blend prepared from the ethyltrimethoxysilyl group containing tetramethyldisiloxanes in Comparative Example 3 and Example 1 to achieve 86.8/13.2 isomer ratio) Precipitated Calcium Carbonate 108.99 Ground Calcium Carbonate 62.1 Methyltrimethoxysilane 7.62 Slurry 80% Titanium Ethyl Acetoacetate 2.76 20% Methyltrimethoxysilane Tetra-n-butoxy titanate 1.26 3-Mercaptopropyltrimethoxysilane 0.87 N-(3-(Trimethoxysilyl)propyl)ethylenediamine 0.39

Amount Speedmixer Component (g) Sample 32 Polydimethylsiloxane 100% end capped with 171.9 96.4% β ethyltrimethoxysilyl group containing tetramethyldisiloxane and 3.6% α ethyltrimethoxy silyl group containing tetra- methyldisiloxane (the ethyltrimethoxysilyl- terminated tetramethyldisiloxane prepared as in Example 1) Precipitated Calcium Carbonate 108.99 Ground Calcium Carbonate 62.1 Methyltrimethoxysilane 7.62 Slurry 80% Titanium Ethyl Acetoacetate 20% 2.76 Methyltrimethoxysilane Tetra-n-butoxy titanate 1.26 3-Mercaptopropyltrimethoxysilane 0.87 N-(3-(Trimethoxysilyl)propyl)ethylenediamine 0.39

Amount Speedmixer Component (g) Sample 33 Polydimethylsiloxane 100% end capped with 171.9 65% β 35% α di-ethyltrimethoxysilyl groups (prepared as in Comparative Example 6) Precipitated Calcium Carbonate 108.99 Ground Calcium Carbonate 62.1 Methyltrimethoxysilane 7.62 Slurry 80% Titanium Ethyl Acetoacetate 2.76 20% Methyltrimethoxysilane Tetra-n-butoxy titanate 1.26 3-Mercaptopropyltrimethoxysilane 0.87 N-(3-(Trimethoxysilyl)propyl)ethylenediamine 0.39

Amount Speedmixer Component (g) Sample 34 Polydimethylsiloxane 100% end capped with 171.9 (prophetic) 95% β 5% α di-ethyltrimethoxysilyl groups Precipitated Calcium Carbonate 108.99 Ground Calcium Carbonate 62.1 Methyltrimethoxysilane 7.62 Slurry 80% Titanium Ethyl Acetoacetate 20% 2.76 Methyltrimethoxysilane Tetra-n-butoxy titanate 1.26 3-Mercaptopropyltrimethoxysilane 0.87 N-(3-(Trimethoxysilyl)propyl)ethylenediamine 0.39

Creep Recovery SOT TFT Sample Description (%) (%) (min) (min) Sample 29 66.4% β ETM 1940.3 2358.1 15 41 (comparative) Sample 30 76.6% β ETM 192.5 58.5 10 34 (comparative) Sample 31 86.8% β ETM 95.5 11.5 13 30 (comparative) Sample 32 96.4% β ETM 98.3 13.7 6 23 (practical) Sample 33   65% β EHM 72.8 6.4 4 17 (comparative) Sample 34   95% β EHM 23 1.4 1 11 (practical)

Amount Speedmixer Component (g) Sam- Polydimethylsiloxane 100% end capped with 158.22 ple 35 66.4% β ethyltrimethoxysilyl group containing tetramethyldisiloxane and 33.6% α ethyltrimethoxy silyl group containing tetramethyldisiloxane (the ethyltrimethoxysilyl-terminated tetramethyldisiloxane prepared as in Comparative Example 3) Precipitated Calcium Carbonate 131.22 Methyltrimethoxysilane 7.26 Slurry 80% Titanium Ethyl Acetoacetate 20% 3.3 Methyltrimethoxysilane

Amount Speedmixer Component (g) Sam- Polydimethylsiloxane 100% end capped with 76.6% β 158.22 ple 36 ethyltrimethoxysilyl group containing tetramethyldisiloxane and 23.4% α ethyltrimethoxy silyl group containing tetramethyldisiloxane (the ethyltrimethoxysilyl-terminated tetramethyldisiloxane used in this sample was a blend prepared from the ethyltrimethoxysilyl group containing tetramethyldisiloxanes in Comparative Example 3 and Example 1 to achieve the 76.6/23.4 isomer ratio) Precipitated Calcium Carbonate 131.22 Methyltrimethoxysilane 7.26 Slurry 80% Titanium Ethyl Acetoacetate 20% 3.3 Methyltrimethoxysilane

Amount Speedmixer Component (g) Sam- Polydimethylsiloxane 100% end capped with 86.8% β 158.22 ple 37 ethyltrimethoxysilyl group containing tetramethyldisiloxane and 13.2% α ethyltrimethoxy silyl group containing tetramethyldisiloxane (the ethyltrimethoxysilyl-terminated tetramethyldisiloxane was a blend prepared from the ethyltrimethoxysilyl group containing tetramethyldisiloxanes in Comparative Example 3 and Example 1 to achieve 86.8/13.2 isomer ratio) Precipitated Calcium Carbonate 131.22 Methyltrimethoxysilane 7.26 Slurry 80% Titanium Ethyl Acetoacetate 20% 3.3 Methyltrimethoxysilane

Amount Speedmixer Component (g) Sam- Polydimethylsiloxane 100% end capped with 96.4% β 158.22 ple 38 ethyltrimethoxysilyl group containing tetramethyldisiloxane and 3.6% α ethyltrimethoxy silyl group containing tetramethyldisiloxane (the ethyltrimethoxysilyl-terminated tetramethyldisiloxane prepared as in Example 1) Precipitated Calcium Carbonate 131.22 Methyltrimethoxysilane 7.26 Slurry 80% Titanium Ethyl Acetoacetate 20% 3.3 Methyltrimethoxysilane

Amount Speedmixer Component (g) Sam- Polydimethylsiloxane 100% end capped 158.22 ple 39 with 65% β 35% α di-ethyltrimethoxysilyl groups (prepared as in Comparative Example 6) Precipitated Calcium Carbonate 131.22 Methyltrimethoxysilane 7.26 Slurry 80% Titanium Ethyl Acetoacetate 3.3 20% Methyltrimethoxysilane

Amount Speedmixer Component (g) Sam- Polydimethylsiloxane 100% end capped 158.22 ple 40 with 95% β 5% α di-ethyltrimethoxysilyl (pro- groups phetic) Precipitated Calcium Carbonate 131.22 Methyltrimethoxysilane 7.26 Slurry 80% Titanium Ethyl Acetoacetate 3.3 20% Methyltrimethoxysilane

Creep Recovery SOT TFT Sample Description (%) (%) (min) (min) Sample 35 66.4% β ETM 30.8 2.5 13 19 (comparative) Sample 36 76.6% β ETM 27.4 1.9 7 16 (comparative) Sample 37 86.8% β ETM 18.0 1.2 11 23 (comparative) Sample 38 96.4% β ETM 14.7 1.0 4 18 (practical) Sample 39   65% β EHM 10.8 0.6 2 8 (comparative) Sample 40   95% β EHM 5.8 0.3 0 7 (practical)

Amount Speedmixer Component (g) Sam- Polydimethylsiloxane 100% end capped with 66.4% β 208.04 ple 41 ethyltrimethoxysilyl group containing tetramethyldisiloxane and 33.6% α ethyltrimethoxy silyl group containing tetramethyldisiloxane (the ethyltrimethoxysilyl-terminated tetramethyldisiloxane prepared as in Comparative Example 3) Precipitated Calcium Carbonate 126.88 Methyltrimethoxysilane 10.15 Slurry 80% Titanium Ethyl Acetoacetate 20% 4.66 Methyltrimethoxysilane N-(3-(Trimethoxysilyl)propyl)ethylenediamine 0.28

Amount Speedmixer Component (g) Sam- Polydimethylsiloxane 100% end capped with 76.6% β 208.04 ple 42 ethyltrimethoxysilyl group containing tetramethyldisiloxane and 23.4% α ethyltrimethoxy silyl group containing tetramethyldisiloxane (the ethyltrimethoxysilyl-terminated tetramethyldisiloxane used in this sample was a blend prepared from the ethyltrimethoxysilyl group containing tetramethyldisiloxanes in Comparative Example 3 and Example 1 to achieve the 76.6/23.4 isomer ratio) Precipitated Calcium Carbonate 126.88 Methyltrimethoxysilane 10.15 Slurry 80% Titanium Ethyl Acetoacetate 20% 4.66 Methyltrimethoxysilane N-(3-(Trimethoxysilyl)propyl)ethylenediamine 0.28

Amount Speedmixer Component (g) Sam- Polydimethylsiloxane 100% end capped with 208.04 ple 43 86.8% β ethyltrimethoxysilyl group containing tetramethyldisiloxane and 13.2% α ethyltrimethoxy silyl group containing tetramethyldisiloxane (the ethyltrimethoxysilyl-terminated tetramethyldisiloxane was a blend prepared from the ethyltrimethoxysilyl group containing tetramethyldisiloxanes in Comparative Example 3 and Example 1 to achieve 86.8/13.2 isomer ratio) Precipitated Calcium Carbonate 126.88 Methyltrimethoxysilane 10.15 Slurry 80% Titanium Ethyl Acetoacetate 20% 4.66 Methyltrimethoxysilane N-(3-(Trimethoxysilyl)propyl)ethylenediamine 0.28

Amount Speedmixer Component (g) Sam- Polydimethylsiloxane 100% end capped with 208.04 ple 44 96.4% β ethyltrimethoxysilyl group containing tetramethyldisiloxane and 3.6% α ethyltrimethoxy silyl group containing tetramethyldisiloxane (the ethyltrimethoxysilyl-terminated tetramethyldisiloxane prepared as in Example 1) Precipitated Calcium Carbonate 126.88 Methyltrimethoxysilane 10.15 Slurry 80% Titanium Ethyl Acetoacetate 20% 4.66 Methyltrimethoxysilane N-(3-(Trimethoxysilyl)propyl)ethylenediamine 0.28

Amount Speedmixer Component (g) Sam- Polydimethylsiloxane 100% end capped with 208.04 ple 45 65% β 35% α di-ethyltrimethoxysilyl groups (prepared as in Comparative Example 6) Precipitated Calcium Carbonate 126.88 Methyltrimethoxysilane 10.15 Slurry 80% Titanium Ethyl Acetoacetate 20% 4.66 Methyltrimethoxysilane N-(3-(Trimethoxysilyl)propyl)ethylenediamine 0.28

Amount Speedmixer Component (g) Sam- Polydimethylsiloxane 100% end capped with 208.04 ple 46 95% β 5% α di-ethyltrimethoxysilyl (pro- groups phetic) Precipitated Calcium Carbonate 126.88 Methyltrimethoxysilane 10.15 Slurry 80% Titanium Ethyl Acetoacetate 4.66 20% Methyltrimethoxysilane N-(3-(Trimethoxysilyl)propyl)ethylenediamine 0.28

Creep Recovery SOT TFT Sample Description (%) (%) (min) (min) Sample 35 66.4% β ETM 58.5 4.1 12 21 (comparative) Sample 36 76.6% β ETM 32.9 2.2 10 16 (comparative) Sample 37 86.8% β ETM 20.1 1.3 10 17 (comparative) Sample 38 96.4% β ETM 12.9 0.8 6 13 (practical) Sample 39   65% β EHM 16.6 0.9 5 10 (comparative) Sample 40   95% β EHM 9 0.4 3 8 (practical)

In this example 47, ethyltrimethoxysilyl tetramethyldisiloxane was prepared in a round bottom flask was loaded with 25 g of TMDS and a stirbar, then capped with an addition funnel containing 20 g of VTM mixed with Ir (0.2 mL of 0.05M Ir solution in toluene, as [Ir(COD)Cl]₂ from Strem). Thermocouples were inserted through a septum into the flask to allow for temperature logging and temperature control. A stream of 98% N₂/2% O₂ was bubbled into the VTM and through the rest of the apparatus for 10 min. The flask was preheated to 50° C., and then a steady drip (1 drop/sec) of VTM/catalyst mixture was added. An exotherm immediately began and gradually rose until the temp approached 70° C. At this point, the heating mantle was lowered which reduced the insulation of the flask and allowed the temperature to gradually fall. After dropping to 64° C. the mantle was returned to the flask and the temperature began to raise again. After the addition was complete, the set point on the heat controller was raised to 70° C. for 20 min, and then heating was stopped and the reaction apparatus was cleaned up.

Conversion to Time ethyltrimethoxysilyl conversion to equivalents % VTM (minutes) tetramethyldisiloxane ethyltrimethoxysilane VTM added consumed 5 3.2 0.6 0.1 37.5 10 17.5 1 0.25 74.1 15 32.3 1.6 0.4 84.8 20 50 1.9 0.6 86.5 25 61.9 3.1 0.75 86.6 30 70.1 3.3 0.85 86.4 35 78.8 3.7 0.95 86.8 45 88.8 3.9 1 92.7 90 94.7 4.2 1 98.9

Within the 94.7% overall yield of ethyltrimethoxy-tetramethyldisiloxane (ETM converter), 97% were linear ETM converter, 1% was branched ETM converter, and 2% was a dehydrogenative silylation by-product (which contained unsaturation).

INDUSTRIAL APPLICABILITY

The examples and comparative examples above show that when a polyorganosiloxane is endblocked with an alkoxy-functional organohydrogensiloxane oligomer prepared by the method described herein and having >90 mol % of linear divalent hydrocarbon linking groups, and the resulting endblocked polyorganosiloxane is formulated into a condensation reaction curable composition, the composition cures faster than a comparative composition containing a polyorganosiloxane endblocked with an alkoxy-functional organohydrogensiloxane oligomer having a lower amount of linear divalent hydrocarbyl linking groups and a higher amount of branched divalent hydrocarbon linking groups. 

The invention claimed is:
 1. A method for preparing an alkoxy-functional organohydrogensiloxane oligomer, where the method comprises: 1) reacting starting materials comprising: (A) a polyorganohydrogensiloxane oligomer of unit formula: (HR¹ ₂SiO_(1/2))_(e)(R¹ ₃SiO_(1/2))_(f)(HR¹SiO_(2/2))_(g)(R¹ ₂SiO_(2/2))_(h)(R¹SiO_(3/2))_(i)(HSiO_(3/2))_(j)(Si O_(4/2))_(k) where subscripts e, f, g, h, i, j, and k have values such that 5≥e≥0, 5≥f≥0, 10≥g≥0, 5≥h≥0, subscript i is 0 or 1, 5≥j≥0, subscript k is 0 or 1, with the proviso that a quantity (e+g+j)≥2, and a quantity (e+f+g+h+i+j+k)≤32; and each R¹ is independently a monovalent hydrocarbon group of 1 to 18 carbon or a monovalent halogenated hydrocarbon group of 1 to 18 carbon atoms; (B) an aliphatically unsaturated alkoxysilane of formula:

where each R² is independently an aliphatically unsaturated monovalent hydrocarbon group of 2 to 18 carbon atoms, each R³ is independently a monovalent hydrocarbon group of 1 to 18 carbon atoms, subscript c is 0 or 1; and (C) an iridium complex of formula [Ir(R⁵)_(x)(R⁶)_(y)]_(z), where subscript x is 1 or 2, R⁵ is a 1,5-cyclooctadiene ligand or a 2,5-norbornadiene ligand, subscript y is 0, 1 or 2, R⁶ is a ligand that can be activated at a temperature less than a boiling point of the organohydrogensiloxane oligomer, and subscript z is 1 or 2, thereby preparing a reaction product comprising the alkoxy-functional organohydrogensiloxane oligomer; and optionally 2) isolating the alkoxy-functional organohydrogensiloxane oligomer prepared in step 1).
 2. The method of claim 1, where (C) the iridium complex is selected from the group consisting of: [Ir(I)(1,5-cyclooctadiene)Cl]-dimer; Ir(I) 1,5-cyclooctadiene acetyl acetonate; Ir(I)(1,5-cyclooctadiene)₂(tetrakis(3,5-bis(trifluoromethyl)phenyl)borate); [Ir(I)(1,5-cyclooctadiene)(OMe)]-dimer, Ir(I)(1,5-cyclooctadiene)(hexafluoroacetyl acetonate), Ir(I) (1,5-cyclooctadiene)(CH₃CN)₂, Ir(I) (1,5-cyclooctadiene)(pyridine), Ir(I) (1,5-cyclooctadiene)(indenyl), and mixtures thereof.
 3. The method of claim 1, where the alkoxy-functional organohydrogensiloxane oligomer has unit formula:

where R¹, R³, and subscripts c, f, h, i, and k are as described above, subscript b is 0 to 2, m>0, and a quantity (m+n+o+p)=(e+g+j), and each D is independently a divalent hydrocarbon group of 2 to 18 carbon atoms, with the proviso that >90 mol % of all D groups produced in step 1) are linear.
 4. The method of claim 1, where (A) the polyorganohydrogensiloxane oligomer has formula:

where subscript a is 0 to
 10. 5. The method of claim 4, where the alkoxy-functional organohydrogensiloxane oligomer has formula:

where D is a divalent hydrocarbon group of 2 to 18 carbon atoms, with the proviso that >90 mol % of D are linear divalent hydrocarbon groups.
 6. The method of claim 1, where (A) the polyorganohydrogensiloxane oligomer has unit formula: (HR¹ ₂SiO_(1/2))₃(R¹ ₂SiO_(2/2))_(q)(R¹SiO_(3/2)), where subscript q is 0 to
 3. 7. The method of claim 6, where (A) the polyorganohydrogensiloxane oligomer has formula:


8. The method of claim 7, where alkoxy-functional organohydrogensiloxane oligomer has formulae comprising:

or both, where each D is independently a divalent hydrocarbon group of 2 to 18 carbon atoms, with the proviso that >90 mol % of D are linear divalent hydrocarbon groups.
 9. The method of claim 1, where the organohydrogensiloxane oligomer is a cyclic organohydrogensiloxane oligomer of unit formula: (R¹ ₂SiO_(2/2))_(v)(R¹HSiO_(2/2))_(s), where subscript s≥3 and subscript v≥0.
 10. The method of claim 9, where the alkoxy-functional organohydrogensiloxane oligomer has unit formula: (R¹ ₂SiO_(2/2))_(v)(R¹HSiO_(2/2))_(t)

where subscript t≥0, subscript u≥1, and a quantity (t+u)=s.
 11. A method for preparing a poly-alkoxy functional polyorganosiloxane, where the method comprises: 1) reacting starting materials comprising: (A) a polyorganohydrogensiloxane oligomer of unit formula: (HR¹ ₂SiO_(1/2))_(e)(R¹ ₃SiO_(1/2))_(f)(HR¹SiO_(2/2))_(g)(R¹ ₂SiO_(2/2))_(h)(R¹SiO_(3/2))_(i)(HSiO_(3/2))_(j)(Si O_(4/2))_(k) where subscripts e, f, g, h, i, j, and k have values such that 5≥e≥0, 5≥f≥0, 10≥g≥0, 5≥h≥0, subscript i is 0 or 1, 5≥j≥0, subscript k is 0 or 1, with the proviso that a quantity (e+g+j)≥2, and a quantity (e+f+g+h+i+j+k)≤32; and each R¹ is independently a monovalent hydrocarbon group of 1 to 18 carbon or a monovalent halogenated hydrocarbon group of 1 to 18 carbon atoms; (B) an aliphatically unsaturated alkoxysilane of formula:

where each R² is independently an aliphatically unsaturated monovalent hydrocarbon group of 2 to 18 carbon atoms, each R³ is independently a monovalent hydrocarbon group of 1 to 18 carbon atoms, subscript c is 0 or 1; and (C) an iridium complex of formula [Ir(R⁵)_(x)(R⁶)_(y)]_(z), where subscript x is 1 or 2, R⁵ is a 1,5-cyclooctadiene ligand or a 2,5-norbornadiene ligand, subscript y is 0, 1 or 2, R⁶ is a ligand that can be activated at a temperature less than a boiling point of the organohydrogensiloxane oligomer, and subscript z is 1 or 2, thereby preparing a reaction product comprising the alkoxy-functional organohydrogensiloxane oligomer; and optionally 2) isolating the alkoxy-functional organohydrogensiloxane oligomer prepared in step 1); 3) reacting starting materials comprising: (a) the alkoxy-functional organohydrogensiloxane oligomer; (b) a polyorganosiloxane having, per molecule, an average of at least two aliphatically unsaturated monovalent hydrocarbon groups; and (c) a hydrosilylation reaction catalyst.
 12. The method of claim 11, where starting material (b) is a polydiorganosiloxane of formula:

where subscript n is 1 to 2,000.
 13. The method of claim 11, where the poly-alkoxy functional polyorganosiloxane has formula:

where each D¹ is independently a divalent hydrocarbon group.
 14. The method of claim 11, where the poly-alkoxy functional polyorganosiloxane has formula:

where each D¹ is independently a divalent hydrocarbon group.
 15. A method for making a condensation reaction composition comprising: 1) reacting starting materials comprising: (A) a polyorganohydrogensiloxane oligomer of unit formula: (HR¹ ₂SiO_(1/2))_(e)(R¹ ₃SiO_(1/2))_(f)(HR¹SiO_(2/2))_(g)(R¹ ₂SiO_(2/2))_(h)(R¹SiO_(3/2))_(i)(HSiO_(3/2))_(j)(Si O_(4/2))_(k) where subscripts e, f, g, h, i, j, and k have values such that 5≥e≥0, 5≥f≥0, 10≥g≥0, 5≥h≥0, subscript i is 0 or 1, 5≥j≥0, subscript k is 0 or 1, with the proviso that a quantity (e+g+j)≥2, and a quantity (e+f+g+h+i+j+k)≤32; and each R¹ is independently a monovalent hydrocarbon group of 1 to 18 carbon or a monovalent halogenated hydrocarbon group of 1 to 18 carbon atoms; (B) an aliphatically unsaturated alkoxysilane of formula:

where each R² is independently an aliphatically unsaturated monovalent hydrocarbon group of 2 to 18 carbon atoms, each R³ is independently a monovalent hydrocarbon group of 1 to 18 carbon atoms, subscript c is 0 or 1; and (C) an iridium complex of formula [Ir(R⁵)_(x)(R⁶)_(y)]_(z), where subscript x is 1 or 2, R⁵ is a 1,5-cyclooctadiene ligand or a 2,5-norbornadiene ligand, subscript y is 0, 1 or 2, R⁶ is a ligand that can be activated at a temperature less than a boiling point of the organohydrogensiloxane oligomer, and subscript z is 1 or 2, thereby preparing a reaction product comprising the alkoxy-functional organohydrogensiloxane oligomer; and optionally 2) isolating the alkoxy-functional organohydrogensiloxane oligomer prepared in step 1); 3) reacting starting materials comprising: (a) the alkoxy-functional organohydrogensiloxane oligomer; (b) a polyorganosiloxane having, per molecule, an average of at least two aliphatically unsaturated monovalent hydrocarbon groups; and (c) a hydrosilylation reaction catalyst; and 4) mixing starting materials comprising (i) a polyalkoxy functional polyorganosiloxane prepared according to steps 1) through 3), and (ii) a condensation reaction catalyst.
 16. The method of claim 15, where the condensation reaction catalyst comprises a titanate catalyst.
 17. The method of claim 16, where the composition further comprises one or more additional starting materials, where the one or more additional starting materials are selected from the group consisting of (iii) a filler; (iv) a filler treating (v) a crosslinker; (vi) an adhesion promoter, (vii) a drying agent; (viii) an extender, a plasticizer, or a combination thereof; (ix) a biocide; (x) a flame retardant; (xi) a chain lengthener; (xii) an endblocker; (xiii) a nonreactive binder; (xiv) an anti-aging additive; (xv) a water release agent; (xvi) a pigment; (xvii) a rheological additive; (xviii) a vehicle (such as a solvent and/or a diluent); (xix) a tackifying agent; (xx) a corrosion inhibitor; and a combination of two or more of (iii), (iv), (v), (vi), (vii), (viii), (ix), (x), (xi), (xii), (xiii), (xiv), (xv), (xvi), (xvii), (xviii), (xix), and (xx). 